I've owned two other Orange Squeezer clones, but not the Mr. Squishy so take this with a grain of salt, but I wouldn't look at it as a peak limiter. Mine certainly weren't great in that regard.
On the other hand, bongo was nice enough to let me borrow a modded CS-3 and it was surprisingly good in this regard. In fact, I've come to realize I want/need two different compressors for my different gigs and I'm thinking of picking up a modded CS-3 for one that requires more peak limiting from slapping and filters.
I've never used the LMB-3 so I can't offer any advice in that regard. On the other hand, I have used a SansAmp which is quite a compressor in it's own right.
