Electrostats

Although I've done tons of reading over the years about conventional driver-based speakers and have owned several, I have some basic questions about electrostats (which I heard once and really liked.)

First, do you have the same problems with the size of the speaker vs. room dimensions as you do with conventional speakers? I would assume so, since the length of a soundwave is the same at a given frequency regardless of the source.

Second, what is the difference betwen less expensive electrostats and more expensive ones? For example, are all Martin Logans about the same in terms of quality of sound reproduction (with the difference being bass extension) or are there sonic differences as well?

What companies should I look at for the best value for my money? I'm looking for a pair in the <$2k used area.

I've read that generally speaking, planars and electrostats at most price points - especially the lower price points - outperform conventional speakers. How much truth is there in that?

Thanks for taking time to educate me on these types of speakers.

Howard