I find the enamels to be more durable, however, the dry time is so considerable (10ish hours for comfortable "Curing" on Humbrol) that I've made a full switch to exclusively acrylic if I can get the colors there. That said, they're both great!
I agree with everyone here, it really ends up being your personal preference. I prefer acrylics because of their ease of use with an airbrush and regular painting brushes. Topped it off with a few coats of Testors Dull Cote. I've only ever had to touch up one spot on my lower torso armor in about 15 troops (due to screws from my rifle scratching up the lower torso ab armor, which has been remedied. I've not had a single issue since). I've painted all my life and strictly use acrylics. I'm a novice airbrush artist, so sticking with acrylics just made sense to me. Much, much easier to clean your brushes/tools with acrylics. Just my two cents
Enamels are way more durable and from what I've seen from everyone's posts on TDH, the more popular choice.
I'm new to this as well. I'm in the middle of painting the JP (learning to airbrush on the fly) and I'm using humbrol enamel. There was a pretty steep learning curve on getting the paint thinned appropriately and not making a mess of things while painting, but overall I'm happy with the enamels and they seem very durable.