Top with proper underground and if you want to have mouse at the usual place.

Have to say for me is the pad of if not the best I've ever had.
I always wanted a pad which is quite thin but never found one until I unfortunately on the Razer Sphex rather met by chance.
I also have a Razer Goliathus for my laptop and that is where I see the difference (normal pad against Sphex) and that should be a conscious.

I use the Sphex on a glass table the pad is therefore great even after 3 months there is no slipping mm, I can because table clean with glass cleaner that makes the pad nothing.

But it should be a quite clear when the surface is a bit rougher as wood surface that her pad so not 100% holding as on glass.
Also, keep in mind that this pad should be at a place more permanent who like to change its Sitzpositzpositon and therefore want to lay down the pad is different here wrongly advised that does not make it long with. (I can recommend the one that Goliathus)

+ Absolutely flat, flat does not work
+ To prevent slipping on smooth surfaces (glass with me)
+ Mouse slides imperceptibly over the pad

-Nothing for people who constantly want to sit differently on the PC, the constant tilt dislike it safe.
-Absolutely nothing for mobile use (with the laptop with you)

Conclusion:
For me super on a glass table with a Razer mouse, it is really the best compy.