I think he got more visibility/recognition from fans when he was on the East Coast, due to earlier games and tv coverage. It's not easy when alot of your games start at 10:30 EST, I watch all the Kings games, even thou it means getting to bed after 1 am. but don' know anyone else in the local hockey circle I know that watch anything past 8 pm. Most of the national coverage is geared towards the East Coast times/teams. Most of those fans only know of him, aside from the SCF coverage, from his tenure with the Flyers and I'm guessing base their valuation on that.
Having seen most of his games since his AHL days, his game changed when he got to LA. He was more 1 dimensional in Philly in that shooting and scoring were his primary interests. He was not much for checking, not as physical and not at driven/motivated. Someone close to him that is in the restaurant biz at the NJ shore that I spoke to a couple years back said that Carter was devastated when he was traded from the Flyers, that it tore him up and some of the criticism of his game then was being lazy, esp in his own end, not backchecking, taking shifts/games off he took to heart after the trade. He's older, wiser maybe. He'll score less goals but his game is more rounded, solid and he's a leader now, something I think came with age more than zip code.
But I think the West Coast timing gives his less visibility.
I don't think he's overshadowed by Kopitar, Kopitar is the better player, more skill, esp defensively. Kopitar just doesn't show that on a regular basis, which is frustrating. He tends to have motivation issues over 82. But he's the better player. Carter is a very good, very dependable 2 way , 2nd line center. And I think he'd be that on any team.