I was running W10 mobile on my L925 for a few months. It was nice, but I did have issues with it being jerky while scrolling for pretty much everything. Personally, I despised Edge browser and used Surfy instead, but different strokes for different folks. I had installed wireless charging into my L925 (which works GREAT!) so I never noticed any battery drain issues as when I'm not using my phone I would just set it on the wireless charging pad.
For me, it was mostly how much it had slowed everything down and the jerky scrolling that made me roll back to W8.1 mobile. Also was the fact that it didn't sound like the L925 would be getting any more W10 mobile updates through the Insider program, so I just rolled back to W8.1 one day when I was bored and felt like spending some time tinkering with my phone. I must say that comparing the features and how efficiently my L925 functions with W8.1, I'm going to stick with it. I'm not feeling left out or disappointed because I don't have W10 mobile on my L925 - it's an older phone and just doesn't have the oomph needed to run 10 as well as it does 8.1. Having my L925 run 10 felt a bit like running XP on a 486 PC - it worked, but not very well.
By comparison, I'm definitely not a power-user like most folks on this site are, so my take is likely more forgiving than others. I mostly just use the built-in apps and don't use the phone for anything other than phone calls, a few texts, checking the weather and browsing a couple of blogs. If I want all the zip-BANG that can come with W10 mobile, I'll purchase a 950XL or some other newer phone that can make use of W10. Most likely, I'll be fine with my L925 for a long time, but I'm curious to see if there will be a Surface phone in the future and see what that will be like.
My opinion is you certainly can install W10 mobile on your L925 via the Insider program and will enjoy it, but you may find some issues that are somewhat annoying, but not really a deal-breaker if you want to be on and using W10. I think you'd find W8.1 to work better on your L925, though. Do what I did - use the Insider program to try it out for a while and you can always roll back if you want.