Disclaimer - I have owned/played a Buster and an MPulse 600, (not 360) and not the Traynor. So, 2 out of 3 isn't too bad
The Buster is actually a great all tube (including the grahpic EQ section) amp that provides a seriously large 200w of tube power. The 2x10 wedge is not the best format for this amp, but put it on top of a Diesel 1x15 (or other quality 1x15) and it will kick some serious butt. If it is in good shape, it is going to be the cleanest tube amp you ever played. So: Clean, Full/Deep Lows, tight mids and high end, LOUD! The Tone and EQ section of this amp is a bit tricky (somewhat like the Fender tone stack) - all the controls interact with each other. So, if you get it, plan to spend some time working with the controls to get the tone you want. A big help is to download the Buster User Manual from the Mesa website.
Mpulse is a very tubey Hybrid, that will strangely sound more tubey than the all tube Buster. Tons of tone control between the basic controls and the para EQ, easy to dial in and plenty of power (solid at 2 ohm operation, even if the manual does not agree). Very much a "Mesa sounding" amp - solid low end, aggressive mids, and clean high end. Over all tone will depend on what cabs you use too of course.
good luck!
As I said, I have no experience with the Traynor amp you mentioned.