Locking tuners are really designed for tremolo systems to be a non invasive alternative to a locknut or stringlock, thus keeping the original head stock intact and free of new holes. It also keeps tuning stability and makes string changes easier. But in order to make tuning stability perfect, you need very slippery nut slots, or the strings will catch when bending the strings and your guitar tuning wont return to pitch. Locking tuners with a lubricated nut can be used in place of those unsightly stringlocks, if you want to keep your axe as original as possible. In order for locking tuners to work properly, your guitar or bass must have a specific type of configuration to it, or it's simply not going to be stable enough for tremolo work.

The best configuration you can have for locking tuners is a head stock with inline tuners like a Fender Stratocaster or a Fender Precision/ Jazz bass has. On these type of head stocks, the tuners are all in a straight line configuration. All the strings will go straight thru the lubricated nut into the tuners without any real bends (a slight down bend from the nut to the tuners is ok and is proper).

The worst situation for locking tuners by themselves is any 3x3 tuner configurations such as Gibson Les Paul's where some strings veer left and some veer right after exiting the nut. These types must use a self lubricating nut to keep in tune. When you tremolo or bend deeply, the windings on the strings will always stick to the outside corners of the nut. Grooves will develop in the nut slots over time.

Most hockey stick type  head stocks like Gibson Explorers or the pointy type Jackson's have, are not a good match at all for a locking tuner and nut setup where the small E string veers downward, across the head stock span to the small e tuner at a sharp angle. Only use a locknut in this situation. However, Gibson V's and PRS's with 3x3's are ok, and are about the only guitars that comes to mind at the time of this writing that will work with locking tuners and self lubricating nuts because the strings go straight thru the nut and into the tuners the same as a Stratocaster does, only in a different design. See the pattern here? Inline Ibanez guitars such as the "RG" or "Jem" series are another perfect situation for locking tuners as well as all older "maple necked", inline head stock Peaveys such as T-60's, Predators and the Mantis ect...

GOOD ADVICE: If the guitar has very sharp bending in ANY string path such as Gibson Explorer or Jackson "hockey stick" type head stocks, be safe, use a locknut. Otherwise stringlocks with a dab of lube in the nut slots or locking tuners and a self lubricating nut are good for all other types, depending on your cosmetic needs.