I just installed it for my new Career playthrough and I love the looks and the building feel of the new parts, however, I feel like this mod was created for the real solar system mod, engines give you very high Delta v than the stock parts? Can someone confirm this or am I wrong? Also I don't like the placement of the parts in the tech tree, it takes away, or even better said, dumbs down the struggle of having limited engines and parts at the start of the playthrough in science or career mode, as well as the reward of unlocking new parts and engines.
I would much rather grind for science and unlock separate nods on the techtree than having a clutter of parts in my VAB/SPH 10 min into career.
I will continue trying all the new parts and playing around but do far I really enjoy the authenticity and the feel of the mod. Good job!