There are no software compressors that can emulate analogue really effectively. Even very
cheap compressors like the DBX 160x and or the RNC are a real blessing when mixing. That
said I really like the UAD 1176 (the newer one) and I'd certainly use a lot of them if I
had a UAD card.
Like everything else, 1176's tend to suffer from the 'new ones
are the same as each other but not the same (as good) as old ones, and old ones are all
different' problem. The usual.
I don't think there's a need to spend pots and
pots of money. Try and few things and see what you think.