I completely understand. It was a fun project, and I really don't want to overstate how bad it was. It was kind of a fun bike, I just often felt like it was fighting against me making it what I wanted it to be.

The thing to notice with my Rockhopper -- and most other mtb-to-drop bar conversions -- is the tall stem with very short extension. I think I've got a 70mm stem on an adapter in that picture. Since mountain bikes are typically designed for flat bars, the top tube is typically longer than it would be to get the same relative reach with drop bars. At least in theory that translates to some difference in handling, though for commuting purposes I'm not sure it matters.

What I really wanted was a cheap, sturdy road bike that would take fat tires. Honestly, the RockHopper got me pretty close to that. A true touring bike (think Surly Long Haul Trucker) is built for heavy loads and so doesn't really feel any more like a road bike than a converted mountain bike does. A sport touring bike like my Sequoia won't take really wide tires. It's limited to around 700x30 with fenders. A sport touring bike converted to 650B gets closer. I've got a Motobecane Grand Jubilé that will take 650x42 tires with fenders, but to get the conversion beyond the sloppy "try-it-out" phase took a decent amount of money.

So I guess you need to decide how wide you want to be able to go with the tires. Really wide? Then a MTB conversion is a decent option if you're willing to give a little in the way of "road feel." If 700x30 is good enough, then a sport touring bike is the way to go. There are a few old bike that will take 700x32, which is more common. Usually bikes from the 70's that originally came with 27" wheels fall into this category. The 27" wheels are close enough to 700c that the brake reach isn't usually an issue, and the bike were designed for wide tires. Here's an example to tempt you:

1972 Motobecane Grand Record. Factory spec was 27x1-1/4" tires (32-630). The tires I have on it are 700x32.