DD1s birth was 2.5 hours and yes I felt quite shell shocked afterwards.....for a few days afterwards when I closed my eyes I kept reliving it and it just left me feeling rather spooked! Like you say, I've often described it as my body was on the 2.5 hour labour schedule but my mind was on the 12 hour schedule! Just never really got a chance to get into the zone, a lot of strategies work with starting something and building it up to match the strengthening contractions but when you seem to miss the slow build up it is bloody hard to start your 'coping' strategies during transition!

While I felt shell shocked I don't think I ever felt like I'd missed out or hadn't had the full experience. I don't know, I guess I don't really buy into the whole idea of an ideal empowering birth etc. so I didn't see it as a lesser experience, birth comes in may shapes and sizes and I just got the concise edition!
BUT for a long time I did feel like I had not 'done' labour very well and had just not handled it well. I think time and having a much calmer (but still quick!) second birth with a better prepared headspace has taught me to cut myself a bit of slack. As a midwife said to me 'you really did your first birth the hard way didn't you?'..... quick is not the easy ride everyone assumes it is, it can be pretty hard so be gentle on yourself