On the last point: storage sizes on laptops have plateaued. I've got a 256gb SSD in my three year old rMBP, and can't see any reason why I'd want more in my new one.
Unless you only use the computer for editing text then storage requirements are growing quicker than ever.
I don't mind paying for the higher end 512GB rMBP, but the discreet graphics is a deal-breaker for me. Thus I'm left with configuring the baseline integrated graphics rMBP with 512GB flash.
1. Driver issues on Linux
2. Discrete graphics failing and taking the whole logic board with it. Most of my laptops have died this way.
3. Battery life
4. Heat