My Guild and my new Martin tune quite well. My old O-16NY however has tuners that need a good throwing out. They are Grover Stay Tites. I am in irons over replacing them with new stay tites for sake of originality or using new Mini Grovers.The Ovation I had before the Martin tuned well but sounded awful. And actually my old FG 180 tuned easiest of all and kept the tune as long as I didn't pound on it.
Don