Is the T56 6 speed that much stronger than the Passion 5 speed?
Passon 5 sp is designed to take a lot of torque-i cant remember the # Jamie told me, but it's equal to or qreater than the snake charmers notchy 5 sp.

Is having 6 gears more important than 5?
Not unless you want more mpg or want to run say 90 mph at 2500rpm and like welding and fabrication

Is cutting the factory transmission / torsion bar cross-member a big deal? Yes, but if done correctly with care it becomes no big deal.

Any other opinions or suggestions on the Passion 5 speed vs T56 6 speed that I have not covered?

I would prefer the bolt on option over the weld in option. Jamie is producing transmissions and wresting with making sure it's 101 percent. I would like to see those of you whom are complaining -i consider you whiners - to do what he has done. I will road course test one someday and i am sure it will work like all the others I have road coursed. 4 speeds in both flavors std 833 and overdrive 833. Bulletproof and vibration/noise free with over 2000 shifts upndown and 130 mph in 4th.

As to availability - those whom are on the list get the product first. This is not wallmart so what does readily available really mean?