If you have a good sub or subs you should always have the crossover at 80 minimum for home theater. Should outperform any full range speaker. I have a Seaton Submersive with my Theos and it sounds excellent. The best of both worlds, great high/mid range speakers with great lows from a sub.
I bought a Stage new for half the price of a Stage X for my Theos. Best center I've had. Seriously doubt if someone snuck in the middle of the night and swapped if with a Stage X if I would ever know.
I have Theos paired with a Seaton Submersive and love it. Certainly exponentially more than a Dynamo 300, but not sure pairing $5k speakers with a $200 subwoofer makes sense. At least get a $500-1,000 sub from Rythmik, PSA or SVS.
Get the ESL's and a solid receiver and don't look back. I bought my Theos right after hearing the Electromotion ESL's at a Best Buy demo. I bought it because of the major difference I heard in home theater/movies over the B&W CM9's I had just bought a few months prior. I was happy with the B&W's...
I bought an older model but new Stage just a month or two ago. Looks exactly like the Stage X which is $3300 but it was $1500, only difference is the tweeter. I got it from Audio Advisor, here:
http://www.audioadvisor.com/prodinfo.asp?number=MLSTAGE%20%20%20DKCHE
Looks like they don't have...
I bought my MartinLogan's specifically for movies. Had a similar experience being introduced to electrostats like you, at Best Buy. They were also ESL's and they played Adele, Transformers, X-Men and I knew had to have them. Bought a pair of Theos within a month.
I recommend doing what I did and getting the older model but still great Stage from Audio Advisor. It's less than half price of the Stage X model.
http://www.audioadvisor.com/prodinfo.asp?number=MLSTAGE%20%20%20DKCHE