KEF LS50 vs Dynaudio Contour 1.3 MkII vs Thiel 1.6

Disagree that Dynaudios are a better speaker than your Thiels.  I think the time and phase coherence contribute to the soundstaging you are getting and would be tough to replicate.  If I'm you, since you seem to like the Bryston sound, I'd sell the B60 and buy a used 3 or 4BSST2 amp to flesh out what you have and use that with your passive pre.  I have found the SST2 to be a big upgrade over the SST so I'd pony up for that version FWIW.  

I was fortunate to have the 1.6es in my system for an extended audition, and I think they're very good speakers.  Especially if imaging and soundstaging are important to you.  I will say that I was powering them with a 100 WPC amp, and substituting a 200 WPC amp opened them up significantly.  Point being, I think your 60 WPC amp is probably not enough to get the best out of your speakers.  And since you're not even using the preamp section of your Bryston I'd strongly consider getting a more powerful amp.  The 1.6es are not big or heavy at all, so not sure you'd be gaining all that much in portability.  All that said, if I were you and wanted to replace your Theils I'd look at a pair of Joseph Audio, Vandersteen, ProAc, or Reference 3A monitors.  They also have outstanding imaging and soundstaging on par with your Theils and do not require as much power to shine.  Best of luck. 

Couple questions.  Do you currently own the 1.6es?  Why do you have both the B60 and a passive preamp?