For any person making up a budget on how much it will cost to have a DAW up a working, they should include the $250/$300 for sonic synth. Before you buy anything, except for your sequencer of course, you should buy sonic synth.
Where to begin. Well, the strings are amazing. The first time I heard the tremolo strings I couldn't believe how good they sounded. There is so much expression and such realism that will you never hear in any free soundfonts.
All the pianos sound so good as well. I could just play with the grity rhodes and wurlitzers for hours.
I really can't say enough about almost all the sounds ranging from ethnic to huge variety of pads and synths. The only sounds that are somewhat lacking are the brass instruments. The saxes sound good, but some of the trumpets are kind of thin. Brass instruments are pretty hard to play with a keyboard and/or program, so that doesn't help the situation. This is the only "weakness" I can see, but you get soooo many quality playable instruments that it really doesn't matter in the end.
About everyone on KVR knows how great squids is and how quick he is to answer your questions.
I could really caretheless about sampletank being red. Its a darn good interface and player for being free with sonic synth. It has crashed on me a few times in fruityloops, but these have been few and far between.
No other vsti or rompler or sampler gives you this variety of instantly usuable sounds. I can't imagine what I did without it...