The UAD + SPL works great, a totally different flav than the others out there like the ones that come onboard with DAW. MOre smooth. Samplitude has a great one, part of their AM-suite of plugs available outside of Samplitude too. Its more bitty on the Attack, great on the backend compared to the UAD and SPL.
the UAD to me sounds more like the hardware, more rack mounted sounding, for lack of a better term, than the SPL plug. To me at least.