All of the above. We do the drive to Laramie frequently (husband is a UW fan), often with our rig as we stay at the Laramie KOA for games, and always take that route if possible. This summer we got to see a guy making a trek alongside the road with a wagon and a team of horses, that was cool.
We just went through there on the Friday before Labor Day (not towing, just in the car). The roundabout construction that Thom mentioned is indeed wrapping up, but it is still a bit of a mess. There's some detours you can take to avoid it. We've done Shields to Rd 56 then followed that back down again.
I also think downtown Ft Collins is a bit iffy when towing because the lanes are very narrow and there's cars parked on the side of the road, sometimes not that well. But that's avoidable too if you exit I-25 at Prospect and take it across to Shields and head North to meet up with 287 that way, or even keep going all the way to Overland, you'd avoid the construction that way too.
For the record, this way is often still faster than I-25 to I-80. And as mentioned, wayyy more scenic.