What sleeping bag to get?

Yosemite in July and the Grand Canyon in February have very different conditions. It's hard for me to imagine one sleeping bag being appropriate for both trips. You are asking one bag to handle full on summer and full on winter conditions. That might be a big ask.

I think you will be happy with the quality and packability of both Zpacks and EE. But I think Derek is right, you can get a bag that will take you down to the teens or lower for grand canyon nights, but I don't think you would be comfortable in it in the 50's in Utah or Yosemite in summer.

The "typical" sleeping bag sold for three season use is a 20 degree bag. Although like Derek and Kevin said, "three seasons" in Yosemite and the Grand Canyon are very different from eachother.

While working at REI, I'd say about 60 percent of the bags sold were 20 degree bags.

At least 60 percent…

And both Zpacks and EE make wonderful equipment. And they are "Local", in my opinion.

I currently have a discontinued 15 degree big Agnes crater mummmy. Also what do people think about the HG Burrow? I noticed it's a much cheaper alternative and the specs seem nice. But does it pack down nice?

http://www.hammockgear.com/burrow-40/

are these any good?

The range is big so I would consider a quilt firstmost. I've had a lot of bags and quilts but my Katabatic Palisaides is what I reach for most often. It's not cheap but it lofts more than any other bag I have other than my WM. It's a 30 degree quilt and wearing a fleece or light down hoody would get you lower. Like all quilts its easy to vent for warmer nights.

I really like the creative designs of the new Sierra Designs Backcountry bag and quilt. I just sold my Montbell bags and ordered one of each. The SD 2-season 800 bag looks like it can handle a big temperature range with the option of venting on top and with your feet.