I shoot 1911/2011 in competition, mostly open...I've been carrying a G19 for years, mostly because it fits me good and holds 15 rounds.. I did pick up a Staccato C and plan to start carrying it more once I get some rounds through it..
I've been shooting the same open gun for 5 years (20k rounds)...I replaced the FP and mainspring when I got it, maybe have changed 1 or 2 recoil springs since...
Any kind of live fire shooting is good practice, as long as you're using proper fundamentals. Shoot .22 speed steel,cheap and good transition practice!
I was skeptical that a bullet feeder would have as much of an impact as everyone said it would...I've had a MBF on my RL1050 about a year now and it's awesome!
If you have the same platform (glock, 1911, CZ) as what your new open gun is, shoot and train with that...otherwise just continue to shoot and practice like normal, shooting is transferable...
A lot of the 200 and in stuff I'll use cheap factory ammo...even steel case as long as it's paper targets...save your good stuff (75-77gr) for the longer range targets...
I went from a 650 to an RL1050 last year and to me that and adding the MBF made a ton of difference...I have however had a couple primers detonate that would have been easy to feel when priming on a 650...