If you plan on hunting different locations, seasons, elevations, there is no ONE perfect bag. I own several bags for myself and my wife in 20 degree increments. I just packed for Hawaii and my -20*F wouldn't work for that, and likewise my +45*F bag wouldn't work for when I hunt the NZ alps in...
I leave on Thursday to Hawaii for the Nov 2 opener of upland birds. Lots of species that we know like quail, pheasant, chukar, but also lots of exotics; Black, Grey, and Erkel's Francolin, Kalij Pheasant, exotic doves, Sand Grouse.
That reminds me. Day 2 on one of my tahr hunts I tore the menuscus in my good knee. For the rest of the trip I was hobbling along and not able to walk far at all. Managed to get a nice buck chamois when he walked into my zone.
No blacktail deer in Idaho. Might not be important to you but for some hunters it is. I guide for cinnamon teal and I'm always booked up 2 years in advance from out-of state hunters.
Choppered up into the NZ alps despite being warned of a major storm system coming soon. The weather at sea level was recorded as 10" of rain driven by 100kph sustained winds with 120k gust for 40 hours straight, then it snowed. I imagine it was worse than that at the top of the alps. Woke up...