Spent a short time looking at some high end frames and TBH it's either because there's so much good stuff out there or because it all 'looks' the same nothing is taking my fancy.
Hate to say it but for ride quality I like the Madones and new generation Giants.
That point about test rides doesn't really cut it for me. If you could keep a test road bike for a week and be allowed to tweek bits here and there then maybe I could get a feel for it, but to take it for a ride from the shop and expecting it to be bob on for you is a big ask.
I rather sadly keep a diary full of comments and measurements of bikes, frames and kit that I've used to work out what will fit and work for me.