I've been using StockWatchPro for a while and my experience is the opposite of what you described. I use scanner every day and it runs pretty fast. I'm running XP and it never crashed or locked up on me. Support guys are helpful and know what they are talking about.
Try http://www.crontech.com/swp
I've tried many software packages and have to say that this one is one of the best I've used for charting and scanning.
I would go with IB. I pay ~$120/month for Stock Watch Pro/QCharts combination which lets me do things that I couldn't with Tradestation. The extra cost gets quickly covered by commission difference.
I use Stock Watch Pro http://www.crontech.com/swp for scanning along with QCharts. I couldn't find anything else which allows formulas to be used in the scanner.
Just came up with this:
Wouldn't it be funny to use "blue screen" snapshot as a screensaver to scare someone sh*tless while they are in the middle of something very important on their comp? :)