and yes like you said : people can use any level geometry exported from 3DSMAX or others modelers if they use C_move and C_trace (no more need of WED and very long compilation time), and levels made of models are a lot more fast than
blocks geometry for the engine (i've tested all that a lot).
No geometry limitation and really fast level construction, for example under 3DSMAX creating stairs, copying rooms , building arches and
other things etc ... is very quick (not like WED).