i think part of his appeal was that he was a complete cartoon in a show full of characters with nuance and ambiguity. pretty much every other major player has a lot more subtlety and depth to them. and while they're all a bunch of gangsters, they each have their own particular sense of morality to them.
whereas gyp was just a fukking straight up, hot-head maniac from jump and didn't deviate from that at all...i mean, almost every scene/convo he ever had, you sort of expected him to snap and do something crazy. there was always some tension when he was on the screen. he clearly wasn't meant to last, so obviously it all worked out in the end. overall, although he grew on me a little, i found gyp to be a bit too over-the-top. they really leaned on that "psycho villain" angle for that season. don't get me wrong, it was entertaining...but it seemed out of place for the show.