If you're someone who likes grinding for sexual pleasure, run - don't walk - to this vibrator.
To be upfront, I'm pretty "meh" on the vibrations of the Ruby Glow. They're okay, but there are definitely more-powerful vibrators out there. If you're just into the vibrations, you might be better off with a Magic Wand and the Liberator Axis to grind against.
If you're someone who can grind against something (pillow, hand, vibrator, chair, etc.) to orgasm, though, it's hard to argue with the Ruby Glow. It's solid, it's firm, and it's pretty much a perfect surface to grind against. As long as you're seated upright (or laying down on it), it provides a really firm surface for clitoral pleasure - and it stays in place! It pretty much provides a hands-free orgasm where you can use your hands for other things (reading adult material, pleasuring a partner, whatever).
It's really comfortable to sit on, but you just gently shift your weight forward, and then it hits the "ooooooh" spot.
As one of the only vibrators on the market for grinding, I'd recommend this one wholeheartedly if you're looking for the grinding sensations.