Here are my thoughts now that I have spent several nights and one that was 20 - 21 degrees as well as a few other 20 degree and few ranging toward 40. Overall , I like it, but there are a few things that are just personal preference etc. It is fine , for me at 20 degrees, so I would say it is very true to temp. I do get small cold spots side sleeping , mostly due to being a pretty narrow fit, but as I get in summer shape I suspect those will go away. I don't care for the center zip actually, which I was sort of surprised at. For me , center zip is sort of an all or nothing proposition. This is not a big deal, because I just orient on the side like a normal bag. The zipper has maybe a feature or a failure which is that it runs really smoothly, which is great. It may run too smooth if you are using it as a quilt / partially zipped , it can come un done. For as smooth as the zipper operates, it can snag a bit on the collar , which is probably due to girth / stress more than anything. Overall, I think it is warmer than comparable quilts i have used, and offers more function, but it also has a few quirks. I suspect I will use it a pretty fair amount, as my go to in temps above mid 20's. Below mid 20's , I am not sure. I have a Marmot that is rated warmer, but if it is actually warmer it is like only a couple degrees. The difference is the Marmot is bigger so I can wear more clothing underneath to push it a bit further, however I will be making a couple modifications to the Marmot for better colder weather performance. My giving it a 20 degree test on the flicker was really just jammy style sleeping, no jackets, long johns etc or anything.
On another note: Angie and I got a FF penguin as a dual sleeping bag (20 degree also). It is not the lightest solo option by any means , but is very comfy. As a dual bag it is really nice and honestly only 4.5 lbs fully configured and a bit over $600 so if you look at it as a dual it is pretty nice and not bad price to performance. As a single its 2lb 14 which is not horrible (big /long version). Once again, slept in it to 20 and was fine, maybe just barely feeling a chill. It is roomy enough that I suspect I could add layers and use the hood and get it to near single digits without issue. As a dual bag it is sub 4 lbs without the hoods. In that regard, the weight to performance and price (barely over $500 sans hoods) is excellent.
One other note, just a personal one. Nothing beats down for warmth and longevity. While synthetic may have a few small advantages / namely cost / and maybe wet climate /care sort of stuff I just don't see any synthetic coming close to a decent to good down bag. Once again , that is highly personal.