I do not want to come across that I'm arguing with semantics here, but Gibson played more consistently and at a higher level during his career than Melvin did. Gibson handled a lot more pressure situations and thrived in the clutch. Melvin was essentially a 2nd/3rd string catcher (I even recall his brief stint w/the Tigers in '85).
Gibson spent 5 season ('98-'02) as the Tiger's color analysis on FOX, but during that time he served as an "pseudo" instructor and would help out in Spring Training. Also, he was cited throughout his later career as to how he would help out youngsters.
This recent article speaks volumes of how Gibson is (especially w/youngsters):
http://sports.espn.go.com/espn/print?id=2817038&type=story
Melvin having managerial experience doesn't suggest much since it doesn't necessarily signify he's a quality one. Let's be honest... He failed in Seattle and got the Dbacks job out of default. He hasn't justified anything as to why he's worth being kept around longer.
I know I'm the ultimate Gibson supporter which makes me more partial to him. Yet, I have been very anti-Melvin for the longest time, but to me he's really affecting most of these younger players. He's best suited for a veteran oriented team (similar to Brenly).
Again, he must learn to play according to his player's strengths. Also, if a player has an excellent game, don't bench him the next when this player might be able to carry the team w/the momentum that he may be establishing.
I know you're not a major proponent of Melvin yourself. If you think I've been discrediting Chip Hale by suggesting Gibson, then I sincerely apologize.
Perhaps this entire exchange is rather moot in the first place, but to me Gibson has proven (even w/out managerial experience) that he does posses the attributes to be a solid manager, whereas Melvin (even with his experience) lacks the necessary leadership skills/qualities.