I went back to 1.57 after trying 1.6 and 1.61 out because the inconsistency in coil power drove me nuts. The most noticeable aspect of it on my machine is the spotlight that illuminates Betty. Soon after upgrading to 1.60, I noticed that the Betty spotlight was flickering, even in attract mode. I changed the LED, checked connections and nothing fixed it. I also noticed that the kick out from the phone scoop was all over the place. One other interesting point was that occasionally after power up, the Betty spotlight would be OK in attract mode. If I played games then, the coils would be more consistent. After another power cycle, it would go back to flickering again and the coils would be all inconsistent again as well.
I went back to 1.57 and all of that cleared up. So once more, I upgraded to 1.61. The first power cycle after the upgrade, everything came up solid, and I thought "good - something must have gone wrong the last time I tried the upgrade." Played a stack of games and enjoyed the new features. Came back the next day, powered it up, the Betty spotlight was flickering again and sure enough, couldn't make the consistent shots I'd been making, and the phone scoop kick out was all over the place again. That's when I noticed that I could repeatedly power cycle the machine and occasionally get everything to work OK.
So I ended up going back to 1.57 and hoped JJP would fix it in the next update. At one point I was going to hook up my oscilloscope across one of the coils and get some screenshots of the differences between versions. I ended up not doing it because I was sure they'd fix it. Looks like I might have to give it a go this weekend.