4th seasons are the last deer season here in Colorado and the closest to the rut, which IMHO makes them one of the most desirable. The downside is the weather. If we get a lot of early snow, everything migrates down, which means into areas where there is lots of private land. Its a crapshoot no matter how you look at it. I know if it were me, I would not want to go into the area cold with no knowledge. It is a short season and you could spend a lot of time looking just to get familiar with it. The other thing is that a lot of the southern part of the unit is on the Southern Ute Reservation.
I've seen some monster bucks in this unit, but almost all were on private or Ute land. If I was putting in for this unit, I definately would spend some time during the summer looking around and learning a little about it. Hope this helps a little.