Wow, Claire, this is a significant percentage of your wardrobe, but so well thought out that I have no doubt you're doing the right thing. I like the stripe dress on you a lot, but YOU have to feel fab in it! And I just culled a dress pretty similar to your first one. It fits, it's conventionally flattering, but does absolutely nothing for me. I put it on and I feel instantly frumpy. Out it went.
I hear you on dress fit. Actually Calvin Klein cuts work very well on me through the body (short waisted, curvy), but I find them all a bit short these days too. I agree that most of the dresses out there seem to be made for a slightly shorter woman. I notice that some brands (at NAS, Vince and Ted Baker) have been making some nice midi lengths that work better for some of us slightly taller gals, but the price points are higher too. Crossing my fingers that the longer length trend trickles down the retail line.