Well i started with a Infinity USB unlimited which had about a 550ms lag, thinking that was a problem as it is a software emulated COM port, i went and got a Infinity USB.
With the Infinity USB, using NewCS on my XP pc that reduced the lag to about 350ms, using NewCS on a linux pc over a lan reduced it again to about 250ms but it still stutters on most key changes, not as bad as it was, but still not something i would call watchable
It seems to maintain the same lag time as long as i leave it running, so thats not a problem
Its real frustrating, so close yet so far!