Personally, I love the CA2A! So good!
However, I'm just not feeling it for the others.
So much of the time when I get all my gain staging right, the other PC comps aren't even touching the signal. When I do bring levels up enough o make them react, I'm just not that impressed with the sound of them. Maybe I'm doing something wrong? Maybe I'm just not getting it?

It would be interesting to see how the compressors are modeled on the hardware items for any company for that matters.
You got code, much of which is available in basic form but Cakewalk as well as all software/plugin developers use algorithms for saturation/distortion; many write code from scratch and include convolution or profiling.
 
That is as much as I know about it and it is probably incorrect.
But It would be good to know how the emulations work as well as they do.
 
I use the PRO CH comps for slower attack settings, like most soft comps they introduce distortion at their fastest settings.
 
I don't have the LA2A. as I have it from another developer already when it was released in X2 or X1.
 
But I will say there is a fluidity in outboard compression from even cheaper compressors over that of software but like many; convenience, recallability is making ITB compression necessary and they are getting better and better.
  

CA-2A is arguably the crown jewel of the PC compressors with Concrete coming next in line.  With that said, the other ones are more than adequate.  I have to say  I often find myself using them mostly because they are right there.  The fact that I don't find myself having to place another compressor in the chain every time tells me  they are just fine for basic channel and bus compression.  I would not ca l that love but I think it qualifies for strong like.

Ah yes, dubdisciple, the Concrete Limiter is awesome, also (IMHO). Up until I got the Concrete Limiter, the Sonnox limiter was my "go-to". Not anymore, the sound of the Concrete Limiter, coupled with the convenience of it, is my new fave.
I still can't seem to make the other PC comps work for me, though. Doesn't anybody else notice that it takes a LOT of signal to even make them respond? Or, am I doing something wrong?  

+1 for the CA-2A compressor. Valuable in every project, especially good on Vocals (just a touch) and for taming wild acoustic guitar peaks.
 
I've used the other Prochannel compressors with much love for many years, and I like that they seem to have a low CPU hit . . . but the new girl in town, the "Fabfilter Pro-C" has me recently spending more time over at her place.
 
rodreb . . . also, what you're saying about the prochannel compressor levels being somewhat low is especially true of the PC4K-S Type Chan compressor . . . yet I've found that when I use it on my Bass Guitar it sounds great even at the low level . . . just would be nice to see the LED flash at a higher level.

I like them all.
 
The Ca-2a is fantastic.  I like the PC76K a lot, too.  The Concrete Limiter is very good - the bass switch particularly.
 
The 4k bus compressor is a gem, both as "glue" on a bus, but also on snare drums, amongst other things.
 
The 4k Channel Comp was my least favourite, but I like it a lot more now that I understand how to use it.  I found it a lot harder to set up than the others initially, but now love it on certain material - when I ignore the metering and use my ears.
 
So yes, there is some "love" for the PC compressors here..
 

I have spent a lot of time with the hardware 1176, and the SSL compressors. While I have not been in a position to AB back and forth between the two I can say that the PC versions seem very close as far as what I hear. The CA2A is just about dead on. In my experience I will have no problem staying ITB with these. BTW, have you done the math on how much it would cost to do a 32 track mix with a hardware 1176 on each channel? My credit card just melted!  

jb101
 
when I ignore the metering and use my ears.
 

Done the same thing. I didn't see the metering lightning up, but listened and heared what was happening.

But am I remembering wrong that there were some who had reported the metering wasn't working in the PC comps?

When I I wasn't getting a response from the meters unless I used extreme settings I thought about this problem reported and just used my ears.

I like the PC4K Bus Compressor.  I like the controls and I understand what they do.  I use it on individual tracks and busses.
 
The workings of the PC76 Compressor are vague to me:)

PC4K bus comp is very good in my opinion. For very light compression the tape sim works sometimes.