Ramrod, You are going to be looking after your machine arent you? I.e. Firewall? AV? Anti Spyware etc?????
Providing you look after it in a "system management" sense, then your mirror raid is still the better option
If your gonna just fill it with junk and crap etc... and get shed loads of spyware, and download porn, and visit sites mandy says you shouldnt be then yeah.... take a backup...
Personally, i would take a ghost backup of your machine anyway, once you have it the way you want it.... so that in the event you need to do a reload, just restore your image to a "fresh" machine, with all drivers installed (admittedly you would need to update the drivers, depending on how long ago the ghost was taken) but sure saves alot of faffing around...
I wouldnt stripe your raid, as per the discussions me you and nemmy had last night