Virtually all recorders that we work with limit file size to 2GB. It is a FAT limitation, but really does not matter as the majority of the decks do a seamless split, and therefore no data is lost. (I cannot remember the technical part as to why there is a 2gb limit.) You should be able to check the manual online to see if it states seamless file splits or just run and test it if need be. I'd be surprised if the H4 is not seamless, especially after having a firmware upgrade to allow 32gb Cards, but it is an older deck, so perhaps.
There are many people that think the Zoom is a fine deck, but sometimes they are more quiet about it. I have never used it, but have heard many fine recordings with it. It all depends on your needs and if you get good or great recordings than that is all that matters. I own a few decks and in terms of smaller ones, by far my favorite is the MT 2496. There are quite a few people like myself that do very well with it, but we keep really quiet, because that is the favorite deck for people who either have never owned it or who have owned it but had issues to bash. I got mine when it first came out and it had firmware issues, but the last 170 recordings or so have been flawless.
As a group, Sony M10 owners are notoriously insecure
. They have to always chime in on any thread and tell you to get the M10. I hope they will take my sarcasm good naturedly. It IS a fine, even excellent deck, but with so many different models to choose from, not everyone agrees that the M10 suits their needs. I am always amazed at how passionate they are about everyone else owning the same deck. I certainly would consider adding it to my decks, but I am worried that like McDonalds and Meow Mix, there is some addictive drug or additive emitted upon opening and tasting the deck that hopelessly addicts you to it.