My cats (like Love4himies) also were switched to Wellness Core kibble and I've been experimenting with wet food. Aside from one can one of my cats turned her nose up at, the canned food incorporation into their diets has been going well. They are getting it at their nightime feeding and have kibble in the morning. I've been keeping a food diary, as I cannot remember what they like otherwise. One of my cats has a food sensitivity issue, too, and will throw up certain foods. But so far, the canned Wellness and Eagle Pack Holistic Select foods were tolerated fine. I haven't been weighing them, but one of them at least seems to have lost some of her belly, which I noticed when I picked her up the other day... now for the other one!
Both are more active now, though part of that could be the changing weather. Someday I'd love to get them on a raw diet. Growing up, I had a cat who ate a lot of mice and her teeth were in great shape her whole life (she was 15 when she passed away).