I'm sometimes amused by a total newbie poster who has bought (or is thinking about buying) a $5k+ bike -- it's tough to make a smart choice when you know so little about cycling. But it seems like you have some actual riding experience, have thought about it a lot, and you're talking about maybe $3k -- which, yes, will get you a bike that is significantly better (and probably more reliable) than one that costs half as much. I say, go for it. But be sure to budget for pedals and shoes, water bottle cages, and a decent computer.
By the way, when I think back on the bikes I've purchased, my only regrets are (with some of my bikes) that I didn't just spend more and get what I really wanted.