the x0xb0x is about 95% a 303 in sound , though the knobs are flimsy horrible things that feel loose and have that "oh shit is it going to breakf" feel to them.

It has a slightly more fuller sound to it compared to a real 303 and the resonance "twang" isnt quite the same.

There is a bloke in australia on ebay right now selling the full kit for about £60 more than you can get it for from the x0xb0x site - but you don't have to hang around for a year on the waiting list.

The acidlab bassline can get close but sounds too clean, almost VA like a patch on a nord modular or something. . Compared to a real 303 and x0xb0x it is very bright and the accent/resonance doesn't seem to twang at all.

The revolution can sound like a 303 at certain settings if you keep the knobs static but as soon as you start to tweak it, it sounds a bit "different"

Of course , I'm being really anal here , I love the sound of a 303 and I'm a purist. I miss mine dearly but would rather chop off my fingers than pay some cunt £1500 for some battered 25+ year old plastic toy monophonic synth/sequencer.

bottom line... get a pre built x0xb0x as their prices are dropping to about 400-500 squid now instead of 700-800 that they once were. Then pay someone to change them damn knobs to metal shafted decent ones.