Well I actually got on to test it since you said premium is focused on level 30+ and here is my feedback:
The server is extremely laggy (i'm from USA also) My ping goes from 100-215 constantly, the first time it's ever done this. My characters cannot walk more than 2 tiles without pausing for half a second, monsters "teleport" half sqm's towards you, and when i let go of my arrow key my character takes an extra step anyways. I really dislike that client, it's ugly and has so many unnecessary bars i must open just to change from full def to full attack, and it feels glitchy. so i wish you the best of luck but i couldn't make it past level 2 with these conditions, sorry!
I'm from Sweden, and I average at around 200ping. Every now and then it spikes to ~1k for a second, but it's no biggie. 200ms = 0,2s delay. It doesn't make you teleport lag or having to pause, that problem is on your end. It sounds like your computer can't handle the OTC, which I assume is the problem, since you aren't used to its layout. Could also be using the wrong graphic settings (it's defaulted to OGL usually?)