A lot of good advice in this thread. I think the Reference 3a would be an excellent choice and so would Neat speakers (talk about an under-rated line of speakers). On the higher efficiency side, the Tyler Acoustics PD15 is another candidate. Never heard the JansZen, but, some electrostatics would also be quite good. Personally, I like the old Quad 57 because it can play soft and the limited bass response would be apartment friendly.
I know that it is very much a rough generalization, but, a lot of high efficiency speakers ARE very dynamic sounding, particularly at lower overall volume levels. I find the full range single drivers to be extremely dynamic, but, most have very limited bass and a very pronounce upper midrange peakiness as part of the bargain. The more reasonably balanced high efficiency horn systems have the big negative of being very expensive and impractical because of the room that they take up. Because of the ability of horn systems to sound amazing at low volume, you can find crazy pictures of huge systems taking up almost all the space in Japanese audiophiles' tiny apartments.