As a Floridian, my store of choice is Publix.
As a Floridian and former employee of Winn Dixie--I wont' shop there unless it is Christmas day and I forgot something and life will not go on without it.
Publix!
As far as which is better, they have been redoing a lot of stores (at least in my area over in Brevard). So those that have been newly built or newly remodeled stand a chance to be cleaner and maybe even organized better.
Bagged salads will be in the produce section, rotisserie in the deli/hot foods: Mojo is my favorite!!!
Pre-made deli food like potato salads and such will be in a cooler case in the deli.
I also love their banana pudding! Some larger publix will have an olive bar. At least my local publix does (a bit far from sea world though).
Produce--not sure what you mean by high end quality...I find that it is fresher and lasts longer than anything I've ever bought at Winn Dixie despite my better judgement. They also have fresh cut fruit--but it is a premium to buy those fruit salads...very pricey per unit. If I'm looking for something partially prepped, they sell sliced water melon and cantaloupe--and though it is pricier than a whole melon...it's cheaper than buying a cut up fruit salad.
Enjoy!