Both myself and my unit have been complimented multiple times by various Marine units... Usually in a snarky, underhanded way, something like "Well, your 10th MTN, so I guess you'll do." or "10TH MTN? Damn... sorry man..." but I think the best one I've heard so far came form a Marine unit training at drum for cold weather, when their commanding officer said something to the affect of "Well, I think you 10th Mountain guys... well, at least you 10th Mountain Infantry guys, are just a bunch of Marines who got lost in the snow and never found your way home. If you ever want to give it another try, we're always looking for recruits."
It was also ALWAYS fun to watch Marines fall out on long ruck marches in three feet of snow... and two inches of compacted ice. We'd always march up beside them and yell OORAH! (though, hooah is even gayer.)
The Poem was good.
10th Mountain isn't a real mountain unit anymore. They were in WW2, and those guys were a tough bunch. The current 10th is still a tough bunch, and some are mountain trained, but not near all. There's just one Mountain unit left (by mission, as stated in their MTOE). That's 86th IBCT (Infantry Brigade Combat Team). Most of them are in VT, most of the FA guys are in Mass and 102 Infantry is in CT. I was in 3/172 Infantry, in the Forward Support Company that supports them (we actually belonged to the Brigade Support Battalion, but were 100% attached to the Infantry). Well, funny thing is, the FSC had all the best shooters of the battalion. We were constantly tagged to run the ranges for the Infantry guys. They finally dropped having us run the rifle zero and qualification ranges, when they gave us the SAW and M240 range. Of course, 2 of us were detailed to range duty there, by NAME.
Now, I'll bust any current or military member's 'nads over his affiliation, but that's just in humor. I've got a lot of respect for my brothers and sisters (in arms), and if you've served, you probably get the jist of that.
As I said to my brother-in-law, after getting assigned to Drum as a Bn CSM in 10th, "Who'd you kill?"