Okay, Radiant 1.6 is really pissing me off now. 1.4 could easily drag thousands of brushes but 1.6 is crashing every fucking time I try to move a relatively complex (but single) large room. ARGH.
I remember back when I was doing a mapping project I would have to switch from 1.5 to 1.4 just to use one feature, though I don't remember what the feature was or anything beyond that