Aside from having a guitar that now hardly ever goes out of tune due to slipping strings, and having the ability to tune precisely because of the great tuning ratio, these locking tuners have made changing strings an absolute dream! It now takes no more than 10 mins to restring the entire guitar and I'm always 100% confident that it will hold its tune. The locking mechanism holds the string tight and secure so I only need to do one turn of the peg.
I would confidently change the tuners of any future guitar to these.
The only thing I would say is that I had to route the holes in my guitar (1996 Squier Strat) slightly to let them fit, but that was no trouble and worth the effort if I'm honest.
They have made a noticeable difference to the sustain of my guitar. (probably due to the huge jump in quality from the stock squier tuners).
If you are thinking of modding your guitar to get a high quality sound and feel then I would highly recommend them.
They would be much easier to fit to a Mexican made fender or american standard. But if you are up for a little bit of work then you can make these work on virtually any guitar and it would be worth the effort.