I was going to try and set up each of my planes with a different set up, so that they felt like different planes, rather than having the exact same controls for each plane. The cockpits aren't the same, and there are sometimes lots more things to do in say a 737 than a Lancair Legacy.  Is this what the profile specific controls are for? Do I need to switch them each time, or is that automatically done?

I have different profiles for Concorde and a Boeing 737.

 

One big difference is elevator trim which Concorde doesn't have. It has elevons instead (elevator / aileron combined) and to adjust them it requires a different keyboard action. By assigning a different profile to Concorde I can use the same toggle switch to adjust elevon trim as elevator trim on a Boeing.

 

That's why I have different profiles. I'm sure you will find differences with your aircraft where it would be useful to use the same buttons for different actions depending which aircraft you're flying.

 

And the action is automatic. You don't need to do anything.

Nice, and yes, I do notice tiny differences most of the time, big differences on others. The Legacy doesn't have a reverse thrust, yet all of my jets do (PMDG 777/37 A320.) I'd love the ability to have it set up on my joystick, but am unsure if it should be a button or an axis kind of thing.

Reverse thrust on my Saitek throttle quadrant is initiated by pulling the throttle lever backwards from the zero thrust point. There is a small detent on the Saitek to mark that point. It's not an axis though, it's equivalent to pushing a button. That makes it easy to assign to the reverse thrust command in FSUIPC.

 

I'm not familiar with the Legacy but others may be able to help.

I do this on all my planes and it's very easy with FSUIPC. Just make a NEW profile or NEW, BASED ON if there is a lot of similarity. 

 

For instance, in my GA prop planes I use my Saitek as the normal Throttle Prop Mixture. But on the 737 and DC-9 I use Throttle Gear Flaps.

 

For reverse thrust I use the button at the bottom of the throttle and program it to THROTTLE DECR and set it to repeat while held. That will cause it to reduce the throttle into the reverse range. With FSUIPC there is really no limit to what you can do with your hardware.