I hardly ever carry cash so a few years ago I switched to a card holder. Right now I use this Proenza. I can fit two cards in each slot (there are slots front and back) plus there is a middle so it actually holds quite a lot. I can't imagine going back to a full sized wallet, especially when I'm always carrying small crossbodies and bags that are already heavy enough!
Full size 90% of the time. Everyday life = full sized wallet, evening outings = mini wallet. I rarely carry cash - well, at least a lot of it - so I don't really need anything else besides a card holder and a small pouch. Right now I'm going with a floral Cath Kidston, but I really need to downsize for my shoulders' well-being. I dug up my card wallets last week and have been thinking about switching ever since, but still haven't gotten around to it. I'm thinking pink Liebeskind because it has a zipper compartment for coins...
LV ZCP - four card slots (I have three cards in each one), half the size of most wallets but holds everything I need. I have a full size MK wallet but when I try using it I feel like just the wallet takes up half the space in my bags, so I keep going back to the ZCP.
I downsized to a zippy coin purse (ZCP) after my full size wallet was stolen. I never want to go through having to remember everything that's in my wallet and replace it all again! And I've found that all I really need fits fine in my ZCP. The theft really shook me and I don't think I will be able to use a full size wallet again.
Full size wallet. I like having everything in one place - I've tried the small wallet/separate coin pouch but am just not a huge fan. I don't really do mini bags or crossbodies so fitting a full size wallet in my bags doesn't pose a problem.