I would like to know what are the main differences between Microformat's hRecipe and Schema.org's Recipe and how search engines treat each one.
Besides the differences in code and the fact that the former is open while the latter is propietary, how do search engines treat each one and which one is better to implement, both from a long-term perspective and a SEO perspective?
hRecipe is based on class attributes while schema's Recipe is based on multiple attributes. those are the main differences in the markup; hRecipe is backwards compatible whereas Recipe is not, because it's using html5 data attributes.
the big three search engines say that they'll treat both the same, however i don't buy that; Google has been pushing their web platform(s) long enough for me to think that they'll be adding extra juice to Recipe, even though i can't prove it. even if they aren't throwing extra seo at Recipe, you can be sure that they'll work something into SERPS so that if you are using their proprietary markup, you get noticed....more. take the link element's prefetch and prender attributes as an example; google created prerender and if you use it on your site, voila, it prerenders in SERPS for the user. prefetch does not.
i'm not sure how to differentiate between a long-term perspective or an seo perspective, i look @ them the same; i'm not saying that you can't, just trying to explain more. i have thought this over before from a clients perspective and asked myself these same questions in regards to microformats as a whole vs. schema. it's basically a judgement call: microformats are tried and true format; there are millions more sites using micoformatted data than there are using schema's. they aren't going anywhere. and (as noted earlier) they are backwards compatible.
that said, schema is backed by the big three, and being html5 based, shouldn't have portability problems in the future. also previously mentioned, i'm sure all three will be rewarding users (though i have no proof) in their respective search results. one caveat here though, is how fast everything on the web is moving; just as quickly as Schema popped up, it could conceivably be dropped. i doubt it (though i'm hoping) but it is a possibility.
i can't say which is better to implement, but microformats are certainly much easier to implement, they're class based and so freaking easy.