Just for counterpoint, I have a full containment halo seat from Ultrashield and I am down in the thing.Personally I think we should require halo seats but that's another topic.
I got, by accident the 10 degree layback seat and it took a ton of work and fiddling to get it in the right spot so that i was comfortable, could reach everything and still safely get in and out. Now I'm not as tall as Tom, but this may be a disadvantage as I have to be closer to the wheel which gives me less space to get out of the window.
After getting it right, without pedal spacers but with a couple of wheels spacers, i can get out quickly without taking off the steering wheel. It took a lot of practice but it's worth it. It can be done, and hopefully you won't have to do it more than once for real if at all!
The biggest hangup on my setup is that the HANS and shoulder belt get tangled up and catch on the halo portion. I solved this by using surgical tubing attached to the belt and the roof so when I unbuckled, the belt pulled away quickly. I've since taken that off with the new belts but it is an option.
Also, they consider, as do I, your coolsuit connections as breakaway and will let you disconnect them prior to testing you getting out of the car, at least they do up here.