Schema.org with Google, Bing, Yahoo!, and Yandex
Since you asked this question, Microformat's hRecipe has been updated with microformats2 as h-recipe, but otherwise your question remains relevant and is worth answering more than 6 years later.
…how do search engines treat each one…?
Search engine giants, Google, Microsoft (Bing), and Yahoo!, along with Yandex (a popular search engine in Russia and elsewhere globally) collaborated to create Schema.org and the schemas therein.
This collaboration is the biggest differentiator between Schema.org and Microformats; it does and will likely continue to have an impact on how each treats schemas defined by other parties.
You can read about why they created it and how they treat other formats in the Schema.org FAQ.
Specifically, you may be interested in their answers to…
…which one is better to implement, both from a long-term perspective and a SEO perspective?
The schema better to implement is the one with the most support; in this case, that appears to be Schema.org's Recipe. While all of the above search engines still support microformats, mentions of it have disappeared from some of Google's official documentation regarding structured data and rich snippets.
Interestingly, Google recommends a newer syntax for structured data called JSON-LD.
JSON-LD: The future of structured data?
From a long-term perspective, you may want to consider adopting the evermore popular JSON-LD markup syntax with the Schema.org Recipe schema, which even Bing is supporting now ( here are examples demonstrating it ) despite their documentation having no mention of it.
Pinterest's interesting support
The popular content discovery platform Pinterest supports both schemas and even supports the new JSON-LD syntax (though it is not explicitly mentioned in their documentation).
Despite Schema.org's growing popularity and adoption, Pinterest offers seemingly greater support for the h-recipe microformat with their inclusion of e-instructions
as a supported class, whereas Schema.org's corresponding recipeInstructions
property is not a supported property.
It's unclear if this is intentional or even which schema they actually prefer, but it is worth keeping in mind if you intend to develop specifically for this platform.