about multi fx i ve tried various units from low end to pretty high end stuff here my experience :
digitech studio quad : pretty cool 4 I/O unit really cheap n can be quite handy on stage , quality is ok
Ensoniq dp4 : this unit roxxx big time, 4 I/O too, this unit has caracter n good algos n lots of modulations in it , n it does disto very well, perfect for house, tekno, wonderful ensoniq chorus n flange nothing come close imo, if you can find a DP pro is even better! if you play guitar get the dp4 + its had front guitar input.
tc fireworx : crazy fx unit, m2000 rev algos, all the digital n analog i/o you ll ever need, very good converter, lots of controls n modulations, kind of box that does everything that the other dont ! this has a dark side of the moon preset lol. amon tobin use one for example
TC powercore : this is the big deal !! most realistic reverb you can find... system 6000 algos are dope, vss3 non lin dvr2 , MD3 !!!! i bought the MD3 package during xmas for half price i m the happiest man in the world lol, this is less hype than UAD but roxxx much better. its hard to explain as i m not really using it well but check out tc website , you can find pretty cheap powercore firewire on ebay, but i ll suggest investing into the powercore 6000 system, will save you a lot of money !!! from uk is like 2400e
was my lil 2 cents