My husband and I are both transplants, as are many of our friends. I don't know hardly anybody who has moved here because of the "pot" laws. Of our friends who are not natives, every single one of them has moved here for jobs... mostly in oil and gas or in tech/IT/software industries. I personally am in software, husband is in IT consulting. He can live anywhere as he works from home or travels, but I can't. I did have an acquaintance that moved here because her husband got a job managing a dispensary for 50k a year, but once they got here and couldn't find housing they could afford to accommodate their family, they went back to Georgia. My parents just moved here too... my mom is retired, my step dad is a school bus driver, which there is a huge shortage of.
As for I-25, I sure am glad I don't commute to Longmont anymore, and I didn't even have to take the worst part of it. Now, when we head to Wyoming (where husband is from), we leave very early in the morning to avoid the worst of the traffic if at all possible.
And, if you want a quick way through Denver to go south, E470 is your best bet. Yes, it'll cost you a bit as it's a toll, especially towing, but the time and aggravation you'll save by not having to go through downtown is more than worth it, in my opinion.