I've spent better'n twenty years wearin' "them there Army boots" and I have a little bit of feedback:

The baseline "recruit boots" draw a serious vacuum in the comfy dept.

However, the suede rough-out desert boots that are now (sadly) general issue are quite comfy, and appropriate for Texas wear. Even though I'm from Oklahoma I've managed to wear out a pair or two in Texas (Ft. Hood)...

"Jungle Boots" feel pretty much like sneakers and have zero ankle support, I've never really liked 'em. I've got a pair of the insulated winter boots, and during the last ice storm, I finally got some use out of them--I give them an A+ for the environment they're designed for.

Note: ANY boot is worn out far faster than you think. If you can roll a pencil underneath any part of the sole (while it is resting on a flat surface), it's time to either get a new pair, or have them retreaded. A good pair of Dr. Scholl's inserts is mandatory if you have high arches; the Army has flattish feet, otherwise.

Try out a pair of the tan desert boots if you're looking for a non-expensive option. Otherwise, read the Complete Walker iv for some ideas in the sneaker_cum_hiking_boot area.