This is one of the few plugins that I can say yes, there were some compatibility issues.  I use this in both Ableton 8 and Logic 9.  It works great with one exception, automation.  I don't use Ableton 8 to actually write music, just perform it, so I don't know if this problem happens in there, but In Logic 9 I cannot get this thing to respond to automation.  I can edit all the parameters and hear the effects on the audio or midi clip, but when I write some automation for those same exact effects....nothing.  I am totally stumped.  I have referenced the manual and looked online to no avail.  The manual was clear enough.  It is a good thing to have because the Replicant is a little tricky when you first start off.  The general configuration and setup is fairly simple but it does have some interesting parameters, such as "the Big Dial" as they call it.  Yes, the typical functions are all easily accessible, as well as the unique functions of this plugin.  I am giving this an 8 out of 10 because of the automation issue.  Other than that, its really great.

SUITABILITY/PERFORMANCE

Besides the problem mentioned earlier, this plugin works wonderfully.  Its a great tool to have for live use if you want some crazy interesting effects.  I set it up with a midi controller and occasionally "whack-out" some drum loops.  Yes, the plugin is stable.  No crashes and no lost presets.  For live use, it gets a 10 out of 10.  Its responsive to midi mapping and sounds fantastic.  For DAW purposes, I give it an 8 out of 10 for due to the automation problem.  So all together it gets a 9. 
I have been using this plugin only for a few months.


OVERALL OPINION

What I like most about this plugin is the crazy/interesting stuff you can create with it.  It is a little weird at first, but once you get comfortable with it, you can really get some wild effects ranging from random pulsing stuff to sweet filter effects to beyond....
Besides the annoying automation problem (sorry that I keep mentioning that, it really sucks though) I do not care for the "Random" button.  I guess it might come in handy if you really don't care what happens.  But, on a few occasions, I accidentally selected it and completely lost whatever sound I was designing.  Because of that, I wish I could just delete it off the interface. 
This is one of my studio partners plugins and he doesn't remember what he paid for it.  The sound quality is great, clean when it needs to be, awful sounding when you want it to be.  I am not sure if there is any other plugin quite like the Replicant.  If so, I have not tried it yet. 
Yes, I would definitely have to have this plugin if my partner hadn't already had it.