Yeah, thats what I would do (and am going to when ive got cash)
also, dont overlook x0xb0x MarOS firmware
yeah x0xb0x is also wicked...TT-303 has the looks down though :)
the TB-3 basically doesn't sound as good as either of the above (has a hard digital edge and can be aliasy) the accent is all fucked up and doesn't really work properly, the touchscreen control method is shit and it's not anywhere near as useful as the TT-303 or x0xb0x - e.g. no CV, limited pattern modes, that stupid scatter thing (which is really bad), no envmod knob etc. Roland dun fucked it up.
MarOS is great but I put a CPU upgrade and n0nx0x in mine last winter and it's just fantastic. I do sometimes miss the gate time adjustment from MarOS though, you can get some really cool, rhythmic, almost clavinet sounding stuff out of it with really short gate times.
what do you like about n0nx0x? I noticed really good song modes, 64 bar, trigger pattern by midi note, that kind of thing...
I am quite interested in another x0x/tt