Laptops are not preventing anyone from installing XP, and you can still buy computers with XP if you know where to look. For example, Vigor Gaming still sells their gaming systems with a choice of any version of Vista or XP. As for the laptops not letting you install, just format your hard drive, and boot into the XP disk and install with your XP key and it will work. If laptops wouldn't let you run XP on there, then they most certainly won't like you running Linux.
As for that RAM, it's not "wasted." What Vista uses that for is whatever he uses the computer for. When Vista starts, it boots the operating system up, loads Aero (if he can take it) a Quick Find Service (to search from the start menu which I find very useful) and to load programs that he uses a lot such as Microsoft Word and Internet Explorer/Firefox into the memory, that way they open quicker. Besides, Vista utilizes RAM that would otherwise be wasting power having free space.
And Vista is a very fast operating system. The only reason it would be slow if it's because of your computer itself. One of my family relatives put Vista Home Premium on a Gateway laptop with 512MB of RAM, a 2.0GHz single core AMD Sempron, and an 80GB hard drive and it still boots up in about a minute. Heck, when I first put Vista on my gaming computer after I built it, and the thing is a beast, it started Vista up in 20 seconds and it still does 6 months later, having stuffing the system with over a terabyte of data (games, HD videos I've recorded, etc). It's all ready to go with all of my programs opened and ready to go in one minute. Vista, if you didn't know also can adapt to faster connections automatically, such as if you have a T3 line at 45Mbps. Vista will be able to tweak itself to use as much bandwidth as possible when downloading, rather than older operating systems like Windows XP which could only take if you are lucky 15Mbps of internet without optimization.
So honestly from experience and being a hard core gamer, I say that Vista is one of the best OS's there is, hands down, no matter what people say. If you don't like Vista sucking up RAM, by all means either get XP before they stop putting it on the shelves pernamently some time in June, or shut things like Aero, Vista's Quick Search off, ReadyStart (the software that loads your commonly used programs into RAM at boot, if that's the name, can't recall), and tell him to get a rid of all of that OEM crap that comes on the computer, such as those support centers and resource intensive anti virus monitors like Norton.
EDIT: Oh yeah, your hard drive speed is what counts as well. A drive with more capacity, that is SATA/SATA Type II/SAS/RAID 0 will work very well, especially if it has a lot of cache and a very high RPM. Also, the OEMs are not selling XP any more is because XP technically only has a few more years left of support, my guess is around 5 years.
