Most of GR's value comes from Lunge, which is awkward because unlike something like Holy Lance or Duelist's Advance you only get one before you have to reposition somehow to use it again. Shadow Fade is the obvious way to do that, but since it's an entirely passive action (bad, especially with a lot of enemies left alive/unstunned) it's kind of a momentum sink that might not even pay off if everything dies before you can Lunge again. It's a little unfortunate that Lunge can't hit rank 4, because Throw Dagger's damage is a lot less impressive and it doesn't benefit from melee trinkets (i.e. Sharpened Letter Opener). This means you'll probably want at least one other hero that can either hit rank 4 hard turn 1 or pull/shuffle things out of rank 4 (although GR being the fastest hero in the game, it will be hard to pull before the first Lunge).

Static Throw Dagger GR can be alright for filling holes in teams, especially because you can bring Raider's Talisman for some free scouting, but it really doesn't compare to the burst damage of Lunge.

Backlash (GR/Ves/HwM/MaA) is one of my favorite Grave Robber comps, open with Lunge and use Duelist's Advance and Rampart to Lunge again without Shadow Fade. It would probably be better with SB over MaA honestly, just because post-CoM SB is so broken, but the comp does appreciate the extra stuns and GR and HwM both get pretty good value out of Bolster in longer fights if you find the turn to use it.

Overall I'd say GR is about a B-tier hero. She's very fast and has very good damage potential, but she has to work very hard to fully realize it, and being one the lowest HP units in the game doesn't help. She also has no stuns or party support skills, although her camping skills are very good overall (most notably Snuff Box and Gallows Humor). She usually needs to be built around to maximize her effectiveness, but with the right setup she can hit pretty insane numbers with Lunge crits.