Went into my local REI to look at the new Exos 2 weeks ago. They had 2 size Large Exos 58 models in stock. CSA said they didn't have or would likely carry the 48 or 38 Liter models. I asked if they had anything similar in weight/size and the CSA threw me a Flash 45 saying, "give this a look." I'm a huge fan of Osprey so I was initially reluctant. Decided to give it a try and got it loaded up with 30 pounds and did the 10 minute store tour. I was very impressed with the fit and comfort. CSA did mention that the pack doesn't fit everyone as well as it fit me.
Here are the specs Exos vs Flash 45 in my size (Large)
Exos 48 51L 1090g
Exos 38 40L 1010g
Flash 45 50L 990g
So the Flash 45 is only 1L smaller than the Exos 48 but is lighter Exos 38; a lot cheaper than either. Purchased.

