Each channel has 4 stereo FX processors.
Not quite - this is about the "send effects", not the channel effects.
@Ram: Think of these as the classic 19'' effect processors you used to use with your mixing desk. They are common to all channels; you can control how much of your signal you send to the effect box ("effect send"), then the signal from all channels will be mixed, processed by the FX processor and returned back to the main mix (usually).
Currently, the DL32R has two dedicated reverb processors and one delay; the DL1608 only has one of each. These are fixed, so processor 1 is ALWAYS a reverb (although you can set the parameters differently between reverb 1 and reverb 2 on the DL32).
The new system, as I understand it, means that:
a) we get more parallel send effecs (4 instead of 3 on the DL32R)
b) we can freely choose what type of effect each slot will be, so if I want three different reverbs, I can have them; if I want one reverb and three different delays - presto! Or any kind of other effect that Mackie will provide (chorus, flanger, exciter, whatever...)
The one limitation however remains: these will still be SEND effects only AFAIK. So no plug-in-effects that you can use as insert on a specific channel. But of course you can abuse a send effect as an insert (send a channel to it pre-fader, mute the channel's main output and use the effect return faderinstead of the channel fader to set volume), but that's a bit convoluted and counter-intuitive.
Cheers,
Torsten