I bought one on a whim and now want 2 more.
They have really brought my mixes to llife and with the new EMT 140 plate emulation they have become the must have for every DAW owner - As far as I'm concerned!
All I can say is get down your local music shop and get one tried out.
Also log onto the UAD forum hosted by
www.chrismilne something something .com as there are rumours of a gorup buy option at the moment - be warned though this is likely to benefit people who have already bought the Studio Pak as I guess the group buy will probably be for a Project Pak (ie less plugs bundled).
Try it wherever possible!
Drammy