I prefer Garth to Kaldur/Jackson at least Garth can have fun with Wally, Donna Dick and Roy. It's just Kaldur is too serious for Dick's team. Tim's team is the serious team. There's a limit of one super serious character or super silly character in each line up. Bart is Tim's goofball and Roy is Dick's super serious.
It didn't really bug me on Kaldur's personality. Most of Kaldur-ahm was based on Garth the low tempered, calm attitude almost pacifist, his affection for Tula, his bromance with Roy, It bothered me that he got replaced because he wasn't a minority Kaldur wasn't really that much of his own character in my opinion the thing though that intrigues me about him though is his connection to Black Manta. I think Geoff Johns did a great job with the character though in Brightest Day the Jackson Hyde version he was more of his own character.