As far as I have ever researched, the Suzuki grips only heat 180 degrees so half the grip stays cold. Compared to Oxford premium grips, you will almost certainly be disappointed, they heat 360 degrees of the grip and are super toasty.
I had Oxford premium grips on my last bike, but wanted the controller to be a bit more stealthy on this one, so I went for Honda heated grips that have the same controller as the Suzuki but heat the entire grip. They aren't quite as hot as the Oxford's but pretty good nevertheless.
Heated gloves are a better alternative if you want your complete hand cosseted it heat, but I don't ride in sub-zero temps and like the convenience of pushing a button for instant(ish) heat as and when I want it whatever I'm wearing.
2015 GSX-S1000FA L6 in Glass Sparkle Black / Candy Daring Red