i have some grovers and they are very good(same exact as those). i cant say anything bad about them.
I have Grovers on two of my guitars, and they both hold up tune pretty good. One of the guitars has a Floyd Rose on it, and it doesn't have a locking nut (didn't come with one for some reason...) and the grovers hold the tuning very well.
Grovers = Great considering the same thing from Gotoh and others costs almost double in most cases.

A good set of grovers will only run you about $45 or so, and do a tremendous job. Some companies like Samick and Schecter use them right out of the gate so saves you some upgrade cosmetic costs
- Schecter C-1 Hellraiser
- B.C. Rich Platinum Beast
- Godin LG EMG
- Peavey 6505+ Combo
- "Mastortion" Pedal 1/6
- Hagstrom HC-15 (1967)

2011 gear:
- Schecter 35th anniversary C-1
- Schecter RAF spitfire solo 6
i put grovers on my sg they are great
89' fender strat
gibson sg specail with grover tuners
standard tele
ibenez gio bass
takamine eg334sc
72'martin d-15
skbps-45 board, lots of pedals
peavey tripple xxx head w/ marshall cab