I personally love fixed backs, Yes they can suck when dailying but if you choose the right one for you you can get by fine aslong as you don't have a 4/6 point.
The difference it makes with spirited driving far out ways the negatives.
In my opinion.
Also I'm pretty sure harness are illegal for road use THEY suck for dailying can't move at all. Can't do anything but hold the steering wheel.