I have a beautiful but difficult ES355, the difficulty being the (not uncommon) lack of tuning stability of the G and D strings, particularly under bending.
I played the guitar in the shop a couple of times before buying it, but I think that since I didn't own it at the time I was a bit gentle with the bends and didn't strum so hard, so the problem only became apparent after I got the guitar home. I was pretty crushed. I'm not an advanced enough player to "play around" the tuning issues and it was distracting me.
The String Butler is amazing. By straightening the 4 inner string pulls, the tuning is much better. Gibson necks still have a fairly sharp break, but if you are only noticing the tuning problems in the D and G, it's ikely the angled pull rather than the break that's causing the problem.
I do have a slight reservation with covering over part of the beautiful mother of pearl inlay on the 355 headstock, but knowing my 355 is now as stable as my Fender is a wonderful result.