Interested in what your conclusions are.
Did a little testing yesterday between those two and to me they sound very different from another, but in that way both give you something where (depending on the track) one might work better than the other:
Townhouse is less pumping, more forgiving, "thicker" adds more bass, sounds wider / more spacious and doesn't bring the highs / high mids upfront as the UAD (or every real?) SSL Bus Compressor does.
UAD Bus Compressor MK 2 is more pumping, more "peaky" /snappy, emphasizes the highs and high mids.
On extreme settings I found the Townhouse doesn't break up as much as the UAD SSL does, but I usually don't use any extreme settings, as I use it on the Masterbus with usually around 2-4db of gain reduction, Ratio 4:1, Attack: 3 or 10, Release: .3 or .6. Genre is Techhouse / Trap music.
So to me there isn't one particular better, those two are just different and you have to choose, what fits the track you are working on better.
Le me know if you have a different perception about this 2 compressors.