You won't get 100ms on an international server. You can expect 400ms if everything is working fine, maybe 300ms if everything is firing on all cylinders, but more like 500ms

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For WoW 300-600ms is considered very good. I've raided 25-man WoW on 500ms latency just fine. MMOs [like WoW] are not that reliant on super fast latency such as a FPS, sure it's nice, but the saying "you are your gear" applies -heavily- in a game like WoW [meaning the equipment you wear and your statistics can override alot of "user skill" ] . In FPS speak : It's like a pistol vs. rocket launcher with alot of splatter damage , your latency won't matter that much if you got the rocket launcher

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The real problem with latency and wireless tech is about it not being consistent, if you have a solid 500ms latency, you can actually adapt+predict [you even get latency addons for this] your actions and be very good. <--- this is where ADSL beats Wireless, not necessarily because of lower latency, but the -stable- latency.
However if it jumps around between 300ms and 1500ms , you're screwed. So i actually prefer a "solid" 500-600ms ping over a "jumpy" 300-900ms ping.
I have not played WoW on Neotel as of yet, i am playing Age of Conan currently [same type of game] , which is also european servers..and i get about 400-600ms , which is considered ok....the in game latency indicator also considers this as "yellow latency" [as in good or acceptable] . In WoW it will also be yellow on a scale of [green,yellow,orange,red] ranked from excellent to bad.
I will definitely be playing Champions Online (and maybe Aion) on my Neotel connection soon, it seems a little more "twitchy" [real time combat] , so we'll see how it pans out.
PS: Obviously this is on Neoflex Data , not those other Neoconnect packages.