We haven't done Chef Mickey's so I can't say either way, but we did LTT and Garden Grill in January, so I can tell you about those.
For us (me!) LTT was NOT relaxing at all. The characters were spaced just so that everytime I sat down and got the kids settled again, here came another character. I just felt like I never relaxed, the kids lost interest in eating, and I like actually remembering that I ate, instead of shoveling food down to get out the door.
GG was a total opposite experience. They had us sit where the kids were on the outside (we were at a u-shaped booth on the bottom level, so you couldn't see too far away, so the kids actually ate, and we also had alot of time to interact with each character. It was a very relaxing meal (plus more scenery! I would do the boat ride before instead of after if possible to understand each "scene" better.
As far as food, LTT was just mediocre...I can do the frozen stouffers route at home if I so choose. Definitely nothing special.
However, we loved the food at GG. I thought the catfish and flank steak were very good, as well as the rolls and the potato casserole was really good too (I know alot of places serve something similar, but I still really like them all!) The kids didn't complain about their chicken, and really liked their dessert also. We went at the end of the lunch hour, and the service almost was a little slow at the end, but I found that pretty much everywhere you would have great service through out the meal, but it was difficult to get them to actually bring you the check so you could leave. Hard to believe since you would think they wanted faster turnover!
Well, that was my experience, for what it is worth!