Thoughts on building a Mid-length upper

[oclvtrek]

I've been kicking the idea of building a mid-length upper around and I wanted to hear some opinions & thoughts about the mid-length concept. I've heard they are more reliable than the carbine and I like the idea of building something a little different. Now that Armalite and RRA are both offering mid-lengths I'm starting to see companies like ARMS take an interest. Is it just a fade or is there really something to it?

Fire away! :D