BIG UAD-2 user here too, i really love how the compressors and eqs does sound and react, especially the updated models for fairchild, Teletronix® LA-2A Classic Leveler Collection and 1176 Classic Limiter Plug-In Collection
basically i find most of their plugins very musical and usable, but to be honest, i´m not a fan of the brainworx stuff that has been released recently for UAD plattform , also the amp sims they offer (softube -> pretty outdated ey?? ) and the new Engl and Chandler didnt got me.
the plugins are a bit pricy, but UA has frequently great offers and reduced prices, you just need to be patient and you can get GREAT Deals from them too for most of their plugins
also they have sometimes good hardware deals, like if you purchase an UA LA610MKII Tube Channelstrip/Preamp, you get a free UAD-2 Duo card with it..
thats not that bad.
i also own the Native Instruments Komplete 9 package which inlcudes lots of similar plugins as what UA offer, but the name and gui similarities are the only common things they share.. not that the NI Plugins are bad, no, they are great sounding too, but very different to UA and less musical (imho)