not the best pc, in the world, but not the worst. considering it has windows xp professional pre-installed. with the addition of a cheap ram upgrade and monitor/lcd, it would be great for the kids or nan for those on a budget or want to save room. i haven't got one myself (i have a core 2 system with 4 gigs of ram & vista) but i used to have a pc of similar spec, and was probably just as quick, thanks to xp being so much better. not sure whether this is hot or cold, i'll let you decide.
Dell GX620 Small Form Factor Pc Tower: P4 3.4, Xp Pro, 80gb, 512ram, Dvd Rw, (refubished) - £99.99 delivered at Big Pockets.