i see you got no help so i thought i would help out. just hope it is in time and you have not bought one yet. If you have i hope that you are happy whatever.

differences i found so far.

4mm thick 7075 aluminium throughout chassis towers etc rather than 3. i think you will find that steering knuckles are the same. they are not on the pro1. i think
lower centre of gravity by lay down servo style.
extra fuel filter

There are some other minor changes that i cant remember like balancing.

It all depends on how much you are paying for each?