I'm certainly no MIDI expert.... back in the day I was a solid user of TTS which is similar. I believe Coyote is the default synth used by BB to give sound to the MIDI instruments in a style which uses MIDI.

As to whether or not Coyote or TTS is "sufficiently good enough" for a final mix..... it's not the tool as much as it is the person using the tool.

I've heard some pretty horrendous renderings of some top quality MIDI sampler instruments and on the other side of that equation, I've heard some absolutely stunning orchestral compositions using nothing but TTS.

Having BB, I do have Coyote in the machine but having Sonar, I also have TTS and selected it to be my default synth for BB.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.