Ok so I have 20 hrs on the dual Sim install. My Ovation has a second battery so my A&P wired them independently to each battery. Most of my flying is 8-10k and I always run ROP. On the initial flight I climbed to 8k, leveled off and leaned to 50 ROP. CHT's went nutz hitting 420 degrees in minutes. After contacting Surefly I was told that the variable timing did not really work well with ROP flying. Decided to switch to fixed and everything went back to normal. Saturday on a long cross country flight Battery #2 failed. The result was exactly the same as the magneto that failed which is why I decided to go with the Surefly. It was a hard bump followed by normal power and than about every 3 min another had bump. Not knowing what was wrong in air, I diverted to the closest airport to check it out. When I did a mag check Sim #2 shut down immediately. To get back home I transferred Sim#2 to Battery 1 and made it home with know issues. Looking back on my decision I would not do it again. I will send my mags off for overhaul and keep handy just in case.
So here is my takeaway pros & cons
Very smooth engine performance
Will be looking for a standby battery power gauge to monitor both battery voltages
No performance difference seen at this point
Hot starts are much better
Faster cold start
