my 1.6a does 2.5 stable on the stock air cooling and 1.8v. I'm probably gonna do a voltmod when I get my alpha because this chip does 2.6 with the current cooling, it's just not too stable. I say go for p4 and ddr. I've been having good luck with intel for the last few months and I've yet to break an intel chip(heh no chernobyls either).
my old axia:
oh, and my p4@2.5 is very close in benches to Jason-Pro's XP @ 1.94 and my chip was significantly cheaper than his.
*edit* here's some linkage to benches:
cpu bench
multimedia bench
memory bench
--Matt