well i don't own a UAD, but I've done alot of homework on this. Personally I was not ready to buy and install multiple UADs and deal with any issues. I do believe everyone when they say UAD sounds fantastic. However, the LM sounds fantastic. I can really hear the differences in the various limiters, compressors, and EQs. I was pleasantly surprised about being able to use it in realtime. The one problem however, is that I AM getting some CPU hit. Not sure why because it is supposed to offload. I just got it yesterday so I still may need to tweak. I am also using the firewire port on my soundcard and that may have something to do with it.
I did a little experiment thought to test the response of pushing this to the extreme. Check out this article:
http://www.uaudio.com/webzine/2003/april/index8.html I did exactly what he said he did to get the sound for black dog by zeppelin, and the LM reproduced this effect 100% perfectly!