Par exemple chez BeHost (hébergeur mono-homé HE), j'obtiens du 13ms Behost<=>HE<=>Telia<=>Cogent<=>Free vers ma co ADSL (qui a 8ms vers Paris) en dehors des heures de saturation Cogent.
Donc 13 - 8 = 6ms avec ~1ms entre ma machine et l'entrée sur réseau HE.
(Ce dont je parle au dessus est en v4, BeHost n'a pas encore de v6, mais selon leur site ça va pas tarder)
Après suffit juste de voir depuis les LG pour la comparaison Cogent/HE: 
Vers LaFibre:
HE PAR01 à ITX2:
1	27 ms	1 ms	34 ms	10ge7-6.core1.par2.he.net (2001:470:0:1b0::2)
2	20 ms	6 ms	6 ms	adeli.equinix-ix.fr (2001:7f8:43::4:3142:1)
3	6 ms	6 ms	6 ms	lafibre.info (2a01:6e00:10:410::2)
HE AMS01 à NIKHEF Ams :
1	60 ms	27 ms	15 ms	10ge11-1.core1.bru1.he.net (2001:470:0:398::2)
2	35 ms	39 ms	25 ms	10ge8-15.core1.par2.he.net (2001:470:0:397::1)
3	27 ms	23 ms	23 ms	adeli.equinix-ix.fr (2001:7f8:43::4:3142:1)
4	24 ms	27 ms	22 ms	lafibre.info (2a01:6e00:10:410::2)
(j'ai l'impression qu'il y a des soucis sur le lien Paris-Amsterdam: Tout le traffic Paris/Amsterdam passe par Bruxelles depuis quelques jours)
HE ZUR01 à EQX-ZUR :
1	16 ms	17 ms	25 ms	10ge7-17.core1.par2.he.net (2001:470:0:246::1)
2	29 ms	43 ms	25 ms	adeli.equinix-ix.fr (2001:7f8:43::4:3142:1)
3	26 ms	30 ms	21 ms	lafibre.info (2a01:6e00:10:410::2)
Cogent AMS:
traceroute to lafibre.info (2a01:6e00:10:410::2), 30 hops max, 80 byte packets
 1  2001:978:1:310::1 (2001:978:1:310::1)  1.161 ms  1.152 ms
 2  be2312.ccr42.ams03.atlas.cogentco.com (2001:550:0:1000::9a36:4a5d)  1.054 ms be2311.ccr41.ams03.atlas.cogentco.com (2001:550:0:1000::9a36:4a59)  1.106 ms
 3  be12266.ccr42.par01.atlas.cogentco.com (2001:550:0:1000::9a36:38ae)  9.596 ms  9.602 ms
 4  be12308.ccr21.par04.atlas.cogentco.com (2001:550:0:1000::8275:312a)  9.835 ms be12309.ccr21.par04.atlas.cogentco.com (2001:550:0:1000::9a36:2742)  10.224 ms
 5  * *
 6  * *
 7  adeli.equinix-ix.fr (2001:7f8:43::4:3142:1)  16.373 ms  16.434 ms
 8  lafibre.info (2a01:6e00:10:410::2)  16.518 ms  16.493 ms
  
Cogent PAR:
traceroute to lafibre.info (2a01:6e00:10:410::2), 30 hops max, 80 byte packets
 1  2001:978:1:323::1 (2001:978:1:323::1)  1.092 ms  2.386 ms
 2  be2108.ccr42.par01.atlas.cogentco.com (2001:550:0:1000::8275:3286)  0.891 ms  0.857 ms
 3  be12308.ccr21.par04.atlas.cogentco.com (2001:550:0:1000::8275:312a)  1.337 ms  1.340 ms
 4  * *
 5  * *
 6  adeli.equinix-ix.fr (2001:7f8:43::4:3142:1)  7.538 ms  7.875 ms
 7  lafibre.info (2a01:6e00:10:410::2)  7.022 ms  7.515 ms
  
Cogent ZUR:
traceroute to lafibre.info (2a01:6e00:10:410::2), 30 hops max, 80 byte packets
 1  2001:978:1:329::1 (2001:978:1:329::1)  1.273 ms  1.307 ms
 2  te0-0-0-3.agr11.zrh01.atlas.cogentco.com (2001:550:0:1000::9a19:2dd)  0.997 ms *
 3  te0-7-0-35.ccr21.zrh01.atlas.cogentco.com (2001:550:0:1000::9a36:39ad)  0.969 ms  0.987 ms
 4  be2295.ccr41.par01.atlas.cogentco.com (2001:550:0:1000::8275:335)  14.879 ms be2296.ccr42.par01.atlas.cogentco.com (2001:550:0:1000::8275:339)  14.815 ms
 5  be12309.ccr21.par04.atlas.cogentco.com (2001:550:0:1000::9a36:2742)  14.664 ms be12308.ccr21.par04.atlas.cogentco.com (2001:550:0:1000::8275:312a)  15.038 ms
 6  * *
 7  * *
 8  adeli.equinix-ix.fr (2001:7f8:43::4:3142:1)  15.890 ms  15.986 ms
 9  lafibre.info (2a01:6e00:10:410::2)  14.764 ms  14.712 ms
Niveau mondial après, je vais prendre deux exemples:
- DigitalOcean Singapour:
HE:
1	8 ms	<1 ms	<1 ms	10ge7-6.core1.par2.he.net (2001:470:0:1b0::2)
2	186 ms	187 ms	187 ms	10ge3-1.core1.sin1.he.net (2001:470:0:2df::2)
3	188 ms	185 ms	188 ms	as133165.singapore.megaport.com (2001:ded::8)
4	*	*	*	?
5	192 ms	199 ms	199 ms	2400:6180:0:d0::31:6001
Cogent, passe par TATA:
traceroute to speedtest-sgp1.digitalocean.com (2400:6180:0:d0::31:6001), 30 hops max, 80 byte packets
 1  2001:978:1:323::1 (2001:978:1:323::1)  0.904 ms  0.954 ms
 2  be2097.ccr41.par01.atlas.cogentco.com (2001:550:0:1000::8275:314e)  0.828 ms be2108.ccr42.par01.atlas.cogentco.com (2001:550:0:1000::8275:3286)  0.938 ms
 3  be12308.ccr21.par04.atlas.cogentco.com (2001:550:0:1000::8275:312a)  0.971 ms *
 4  2001:978:3::f2 (2001:978:3::f2)  0.654 ms  0.621 ms
 5  if-ae-2-2.tcore1.PYE-Paris.ipv6.as6453.net (2a01:3e0:fff0:400::e)  1.082 ms  1.275 ms
 6  if-ae-3-6.tcore1.L78-London.ipv6.as6453.net (2001:5a0:2000:400::29)  8.641 ms  8.598 ms
 7  if-ae-2-2.tcore2.L78-London.ipv6.as6453.net (2001:5a0:2000:500::1)  8.614 ms  8.596 ms
 8  if-ae-4-2.tcore2.N0V-New-York.ipv6.as6453.net (2001:5a0:2000:500::2e)  77.247 ms  77.963 ms
 9  if-ae-2-2.tcore1.N0V-New-York.ipv6.as6453.net (2001:5a0:4500:100::9)  75.751 ms  79.713 ms
10  if-ae-7-2.tcore1.NTO-New-York.ipv6.as6453.net (2001:5a0:12:100::19)  77.200 ms  76.062 ms
11  if-ae-12-2.tcore1.SQN-San-Jose.ipv6.as6453.net (2001:5a0:12:100::25)  145.846 ms  145.232 ms
12  if-ae-3-2.tcore2.LVW-Los-Angeles.ipv6.as6453.net (2001:5a0:1000:500::a)  146.805 ms  150.025 ms
13  if-ae-7-2.tcore2.SVW-Singapore.ipv6.as6453.net (2405:2000:ffa0:200::11)  349.598 ms if-ae-12-2.tcore2.TV2-Tokyo.ipv6.as6453.net (2001:5a0:fff0::3a)  274.129 ms
14  if-ae-2-2.tcore1.SVW-Singapore.ipv6.as6453.net (2405:2000:ffa0:100::1)  352.667 ms  353.889 ms
15  if-ae-11-2.thar1.SVQ-Singapore.ipv6.as6453.net (2405:2000:300:100::d)  350.972 ms  348.741 ms
16  2405:2000:300:100::92 (2405:2000:300:100::92)  324.978 ms  329.404 ms
17  * 2604:a880:ffff:9::21e (2604:a880:ffff:9::21e)  328.121 ms
18  2400:6180:0:d0::31:6001 (2400:6180:0:d0::31:6001)  331.820 ms  334.287 ms
Autre exemple:
BuyVM, New Jersey:
HE:
1	1 ms	20 ms	<1 ms	10ge7-6.core1.par2.he.net (2001:470:0:1b0::2)
2	74 ms	75 ms	74 ms	100ge10-1.core1.nyc4.he.net (2001:470:0:33b::1)
3	99 ms	74 ms	75 ms	10ge5-1.core1.nyc6.he.net (2001:470:0:259::2)
4	*	*	*	?
5	84 ms	88 ms	79 ms	vl23-br2.pnj1.choopa.net (2001:19f0:1000::6c3d:f805)
6	78 ms	77 ms	86 ms	vl116-c5-14-b5-1.pnj1.choopa.net (2001:19f0:1000::6c3d:f4f2)
7	80 ms	77 ms	77 ms	2001:19f0:0:1a::2
8	77 ms	86 ms	77 ms	2605:6400:10:53::1
Cogent:
traceroute to nj-test.buyvm.net (2605:6400:10:53::1), 30 hops max, 80 byte packets
 1  2001:978:1:323::1 (2001:978:1:323::1)  0.972 ms  1.012 ms
 2  be2108.ccr42.par01.atlas.cogentco.com (2001:550:0:1000::8275:3286)  0.969 ms  2.368 ms
 3  be2746.ccr41.jfk02.atlas.cogentco.com (2001:550:0:1000::9a36:1d75)  71.179 ms be2747.ccr42.jfk02.atlas.cogentco.com (2001:550:0:1000::9a36:1fbd)  71.176 ms
 4  be2057.ccr21.jfk10.atlas.cogentco.com (2001:550:0:1000::9a36:50b2)  71.696 ms  71.839 ms
 5  2001:550:2:96::3:2 (2001:550:2:96::3:2)  73.117 ms  73.834 ms
 6  vl23-br2.pnj1.choopa.net (2001:19f0:1000::6c3d:f805)  75.276 ms  74.855 ms
 7  vl116-c5-14-b5-1.pnj1.choopa.net (2001:19f0:1000::6c3d:f4f2)  71.978 ms  72.080 ms
 8  2001:19f0:0:1a::2 (2001:19f0:0:1a::2)  77.050 ms  76.996 ms
 9  2605:6400:10:53::1 (2605:6400:10:53::1)  71.905 ms  72.304 ms
En plus du lien Paris-Singapour, HE.net a un lien direct Afrique du Sud-Londres:
1	183 ms	166 ms	172 ms	10ge3-11.core1.lon2.he.net (2001:470:0:291::1)
2	177 ms	196 ms	180 ms	100ge5-1.core1.par2.he.net (2001:470:0:2ce::2)
3	174 ms	174 ms	174 ms	adeli.equinix-ix.fr (2001:7f8:43::4:3142:1)
4	174 ms	231 ms	174 ms	lafibre.info (2a01:6e00:10:410::2)
Après chacun son avis/ses besoins, pour le national+Amsterdam+les US je dirais Cogent et pour l'Europe+l'Afrique+l'Asie => HE si je pouvais choisir que ces deux là ;-)
Sinon TATA, GTT, NTT et surtout Telia sont de bons transitaires aussi ;-)
Level3 j'ai pas encore fais chauffer leur LG 
