I've been reading these forums for a while, but the recent ARM debate has gotten me to finally register You can make SSTOs really easily, but that isn't the point. The point is to put something into space that does something. The new parts are excellent, before these parts I was strapping orange fuel tanks and skippers / mainsails together in onion staging which was slow, tedious, and kind of unrealistic. Now, I can take that pack of orange fuel tanks and replace it with one large booster and engine, which means the first stage of my rocket is far simpler and pleasant to look at. The new parts aren't OP, they are just replacements for the old way of strapping together a bunch of orange fuel tanks and main sails to make the first stage of your heavy lifter. You don't even need the new parts for a lot of stuff, they are really just there to make heavy lifters. It's the thing you are lifting that matters. As for balance, these new parts are expensive. Once career mode rolls into full swing I'm willing to bet these are going to be a little less attractive.