Ok, i have the 10-48 flatwounds on the Casino(ECG23)which are considered lite gauge strings. I like these, but the purpose of this post is that i am astounded that after being out of the case once since last September, These strings were still in perfect tune. Flippn' amazing. I have a Peterson strobe, and when that sucker is caged(within 0.1 cents, or 1/1000 of one semitone)it just don't get any better than that. I know that of course the guitar itself has to be stable, but for you guys that like flat wounds, these are really nice. I use the casino for jazz, surf, some types of rock'n roll, but for everything that my fenders and gibsons can't do. There are just some sounds you can't get with round wound strings. Remember too, that Lennon's casino would have had nylon saddles, and in 65 it might have come wuth flat wound strings. At any ratem these are nice flat wounds that are a pleasure to play, your fingers will thank you.