Can you simply "play" Pulsar synth tracks into it and then have each take on a different track?
Answer: yes, easily.
Can you drop STS wavs in?
Answer: I don't know what an STS wav is but if it conforms to the MS WAV standard then I'd say it probably can. Maybe someone else can answer this question.
What do you mainly use it for?
Answer: TripleDAT basically does one thing and one thing only: multi-track audio recording. It does not have the sequencing capabilities like Cakewalk or Cubebase (although it does support MIDI implementation) I use it much like you'd use a normal multi-track tape deck, specifically, to record tracks for CD audio projects. Also, it doesn't do video like Vegas Audio.
Does it have any horrible bugs or weaknesses ?
Answer: Horrible? No. Annoying? Yes. Some of the obvious weaknesses in 3.11 were mentioned above already. I'll give you a brief list of strengths & weaknesses (based on my humble opinions

.
Strengths:
Easy editing of samples & waveforms. Bit-level surgery is a breeze. Crossfades, volume & pan curves, etc. handled easily.
Built-in FX (especially considering that this new version has Firewalkers & Osiris) which are costly add-on's in other packages. I paid $400 just for Osiris alone. I think Osiris is probably the best noise reduction program on the market - works in realtime!
Simple & clean user interface. TripleDAT's simplicity is really a strength in my opinion. Other programs have more bells & whistles but are also harder to master and are less stable.
I can easily process 24 tracks or more on a PIII 750MHz with 256M RAM. Actually, I remember one arrangement where we had close to 40 tracks running. Pretty cool!
CD writing capability in 3.06 (or earlier) only. This is a biggy in my opinion. Record, edit & burn all in one nice bundle. You might be able to retreive this capability by downloading one of the previous versions from Creamware's FTP site. 3.06 won't work without tripleboard but you might be able to get to the specific files needed for CD writing.
Weaknesses:
As I mentioned before, Creamware hasn't updated this program in over 2 years. I don't know if they have plans to do anything more to it. If you are expecting to see frequent updates, this is not the program for you.
No CD writing capability (removed in this version for DSP users only). I mention it again, only if you're not able to incorporate the feature from a previous version.
No reverb FX although you can get that from a previous version (prior to 3.06). Many didn't see this is a problem since the original Room Simulator had a quality about equal to a low-end rack-mount unit or stomp box.
Some minor appearance problems as I mentioned before.
No Direct x support but many don't see this as a weakness. You are locked into the FX that come with the program. Again, not a big deal since you can easliy add better FX through Pulsar.
Bottom Line: $228 USD seems like a very good deal for this program, warts & all. Original customers paid a lot more, believe me. The strengths outweigh the weaknesses. If you're looking for more features, better support, etc. - look elsewhere.