Ill throw my two cents in, for what its worth. I have young kids at home, so my priority is to get a line quickly and be home as much as possible, Id have a line with the 73, but I chose what was familiar to me, and I am more than okay with it. Been here for about six months, had a line last month, back on reserve this month (probably my fault for helping out my more senior friend bid), hoping for a line next month. Came from a previous bus operator, and glad my sentence was up. At this point of my tenure, the 73 is starting to get the better seniority by about 8%, and I'm guessing that number will go up in the future. Coastal bases do carry the better seniority obviously, but I already commute as it is, so I'm fine where I am at.
As stated previously, the 73 crew will be complaining about sunburns from the Bahamas while you're dealing with an apu that wont start in Bozeman when its -53F out. In my base, we do get some Mexico flying, but it is sparse/goes senior (as you might imagine... unless its Mexico City... you'll see that for sure as a half-winger). 2-3 leg days are the norm, as I have yet to experience the dreaded 4 leg day. All in all, great crews, good overnights (yes even in DSM, and CID when its football season).
Welcome to United, we're glad to have you here.