The Atlas and Catapult especially were kind of wonky compared to the rest of BT scale at the time. The CityTech 2ed minis were huge in comparison. After some craziness between 3067 and 3075 (eg the Stiletto and Warlord), and some that were scaled to... I dunno what (I'm looking at you, Targe), things have settled a bit.
Modern light sculpts tend to fit a bit more with their forefathers. The heavies and assaults are definitely bulkier (Mangonel, Lament, Tian-Zong, Shrike, Shiro, Hatamoto-Suna, etc). Personally, I like the increased heft. Most of the 3145/50 stuff has been excellent. Some have a giant pile of parts like the Atlas III, but they still can get good detail with more basic builds like the Mortis.