I replaced mu old tuners on two of my guitars, because I didn't like that they did not stay tuned and I also wanted a different winding factor. 
I chose Schaller after checking out the guitars' of some friends and I decided to give them a shot. 
PROS: 
- locking tuners, they stay where they should, guitar stays in tune (please note I also changed the bridges, from stock ones to Babicz) 
- good quality, very well built 
- colour stays well even after using them quite intensively 
- great buy for the money, maybe the best in this range 
CONS 
- none that I can tell 
 
It was a good and very inspired decision, it improved heavily the quality of the guitars and eased my life as I don't have to re-tune as often as before. I have two more guitars in my luthier's workshop, they will both receive Schaller tuners.