I played with Hellgate at E32005, when the game was a pure FPS with RPG elements. I really think that they dropped the ball by leaving the FPS genre and going third person/FPS. Mostly because Call of Duty, if it was a futuristic FPS, would be exactly like Hellgate. Exactly, no ifs or buts.
I really fell in love with the gameplay, so for them to drop FPS entirely was a bad, stupid move. Mostly because at the time COD was rising in popularity, and it features the same frantic gameplay, the same FPS/RPG mix, and the same arcade feel (that's what made diablo so popular, IMHO).
Basically, Hellgate (the way it was "released") is a shadow of it's former self.