I used tradestation since version 1.0. ver.4.0 with futuresource sat feed was awesome, great trading s/w plus ability to system test on intraday data. very stable. then came 2000. my experience with it and the PC Quote feed was so bad I trashed it and switched to a cheap internet data/chart service.
It was not nearly as stable or reliable as the prior version, and it crashed everytime the internet went down or the PC Quote feed had a glitch(which was very often). Restarting it takes a while, and if you have a trade on you are toast. Also there was no ability to replace the lost data, except through a cumbersome download at night.
I'm not familiar with their current products, so I can't say if they have corrected these issues. I will say that the backtesting ability is invaluable if you are a beginning trader, well worth the cost of the s/w, provided you have the ability to write and test systems. You do have to be able to get historical intraday data from somewhere though, and in my experience it was not that easy to use Omega.