I agree if all you need is a reverb then the 500/550 is a better idea. It's smaller, much easier to edit, and reverbs sound as good. But the MPX-1 is more powerful as a multi-effects processor, but the UI is horrible.

Sound is decent but not awe inspiring. Big claim to fame is the ITB integration but I'm not sure if they maintain that still. The other big advantage are the knobs, which are a rarity on reverbs. MPX-1 sounds better and is more powerful but requires a lot more menu diving to tweak.

he said price was 1390EU, which is closer to $2000 USD

It's actually the black model but it looks like he swapped out a ton of stuff on it (including new pads and some new buttons). Looks legit, only downside is that it was a live performance so it's one of the few musical items that doesn't have the specious "never gigged, smoke free studio" tagline =)

btw there is a newly listed MPC1000 w/ JJOSXL on Muff's BST right now (I'm not affiliated with that buyer in any form) for $500 + shipping, which seems like a decent deal?

I would not get the 500, that would likely be more frustrating than it's worth. A 1000/2500 or 2000 with JJOS would hook you up pretty well though.

Minor caveat (and which is why I recommend integrating the drum machine and sequencer) is syncing the start/stop/reset between the sequencer and drum machine.

You have a lot of options depending on how you go. Thankfully with the older synths you'll have MIDI THRU available, but I'm not sure how much latency would be incurred with that (it's dependent on the synth's implementation). So you could easily run a straight chain like: sequencer => IN : drum mac...

Seriously, why not the PreenFM2?

http://ixox.fr/preenfm2/

Have you considered the PreenFM?

I would get a KK first. It doesn't have some of the unique weird things of the NL4, but you can get a used one for 1/3 the price of a NL4 (!). KK sounds fantastic, the filters and oscillators sound remarkable for a VA, and it even has CV out that can drive both V/Oct and V/Hz (MS-20). The only real ...

definitely check out CL for deals. Racks are one of those things that people get and then need to get rid of but have a hard time moving because they're very specialized and too expensive to ship (saying this as someone trying to sell a Standtastic 3-tier stand and a 20U rolling rack on CL for MONTH...

Other obvious options are the Lexicon MPX-1 and TC Electronic M350.

I was in a similar conundrum and ended up with the D-Two, which I like a lot. I was looking specifically for something that could do clean delay patterns that were tempo synced.

Mostly testing video stuff (camera + using Reaper), but using some pedals with a Leipzig as well.