I have been using Pinnacle's Studio line since Studio 6. In that time I have also used Final Cut, Sony Vegas and of course Windows Movie Maker and a few other less well known packages.
Pinnacle have had a very chequered history with their products. The story has always been roughly the same: out comes Studio something (6,7,8,9,10 or 11), people buy it and discover that its crap - frequent crashes, many bugs. Then they issue a patch - it gets better, then another patch - better still. Finally (round about the seventh or eigth patch) the product is stable, pretty well bug free and the rich functionality, extremely intuitive interface and good rendering quality can finally be appreciated. Everyone is overjoyed with the product until they bring out the next version and the quality goes back to rubbish again and we all have to wait till it is patched back up to an acceptable level. In short, they issue products before they are ready and treat their customers like unpaid beta testers.
Having said that though the important thing is that once you have the latest patched version of the product you have a damned good NLE which compares excellently with the competition and is a darned sight cheaper.
So the best buying policy is: check on Pinnacle's website what the patch level is for Studio 11 and while you are at it check out their support forum to see if customers have reached the overjoyed stage yet or are still finding bugs. If things look OK then buy this product, if not then find a cheap copy of Studio 10 and patch it (10.8 was I think the last). Being a high patched version it will be stable and bug/crash free and being non-current will be available really cheaply (about 12GBP?)
Studio 10.8 is particularly good - it handles HD, 16:9 PAL screen format and chromakey and lumakey compositing as well as multiple audio tracks, precise L. T and J editing, a wide range of transitions and special effects, DVD indexing and burning. It is also very easy to use and renders in the background. All in all its an excellent tool and you should be able to get it at much less than its original retail price. I dont think it works with Vista though.