Two questions:

Is the Sonitus Multiband Compressor suitable for use in mastering? Or is it known for introducing phase issues? I really don't like the LP-64 Multiband, and from the few times I've used the Sonitus, I like it a lot so far.

Also, for the purposes of a multiband in a mastering situation (i.e. preventing the kick from squashing other frequencies), should it be place before or after the primary master eq? Note that this eq would be used to cut much of the subsonic bass frequencies (@35Hz or so) and prevent these frequencies from wasting the compressor/limiter's range.

I have used it in that capacity, and was happy with the results. I used very soft knees (19-21) and modest (2:1 to 3:1) ratios.

Normally I put EQ in front of compressors, but in this case it worked better the other way 'round.