hmmm, well i must say i've always had better experiences with intels over athlons
we had a p2 300 that run for years like the blazes, then upgraded to an athlon (insert inconsequentsial number here) with the new pc, because it was cheaper.
i now have a p4 on my notebook, its a desktop replacement style thing so its not some watered down chip, i believe its pretty much the same as a desktop processor, and have found it to be far more stable.
speedwise the pentium wins but thats completely irrelevant as they're not meant to be compared, top end laptop chip vs mid/high desktop chip, but stability wise the intel wins, of course it could be any other number of reasons why the laptop is more stable than the desktop.