I've extensively tested a couple of mixers recently (needed 4 channels for Traktor Pro, now I own a djm909):
Crest: Plastic pots in the EQ section, Pre EQ PFL, sound quality so-so. USELESS. What a let-down.
Xones: The 4D would be my weapon of choice if I had a BIG budget, nice MIDIcontrolling options, excellent mixer feel and sound(imo anyway).
Don't like 4 band EQ's so the 62 and 92 are dropped anyway.
Urei: Like the 1620! Though it doesn't suit my needs, I 'need' EQ per channel.
I bought the 1603, i really like its sound, the extensive s/r section and the EQing method, the only issue is the different EQ section on channel one, but I mainly use 3 channels, so I can live with that.
If only Urei (Or E&S...) made a 4 channel EQ/Iso, I'd have chosen the 1620 hands down...