My experiences past and present with Gateway have been quite good. As with any company of this size there's bound to be the occasional hiccup, but for the most part the only gripe I've ever had has been with tech support people. There's a fine line drawn between the experienced techie and the one who simply reads from a list of common ailments. If you get the seasoned veteran techie you're all set. However, if you get the latter, all I can suggest is hang-up and call back.
Setup is as painless as it gets.
All necessary software is pre-installed. The rest of the vast array of included software is available on a stack of CDs. The software bundle has something for everyone. Before I start throwing a ton of benchmarks at you let me just mention that if you are planning on adding equipment to this system, it's a pretty simple job to do so. Two thumbscrews and off comes the main cover.