If the only issue is posbugging, leatrix is particularly likely to help.
Note, however, that you'll still get posbugged if you get hit while moving, use certain skills while moving, etc. Some posbugging is unavoidable, and with practice, you can learn to minimize the impact of that posbugging (by predicting where you actually are)
Services like lowerping and wtfast (both have free trials) will help if the cause of the poor performance is a routing issue (which it often is)
Also, download speed has no bearing on connection performance for almost any online game. What matters is latency, not bandwidth. I am personally aware of people who got acceptable performance playing RO over dialup, and for a while a couple of years back, most people with Comcast cable connections in the north-east couldn't get acceptable performance on RO w/out using lowerping because of routing issues (This is fixed now) - those are a few of the extremes, but yeah - point is, your internet speed is not a useful predictor of gaming performance. Also, the SpeedTest websites are laughable - neither their pings nor their data rates reflect real world performance (though they are useful in diagnosing certain kinds of network performance issues, this isn't one of them).
Edited by DrAzzy, 14 October 2014 - 06:22 PM.