I got the icon pro 1850 couple weeks ago. Same frame. Differnt bag. Get the hip pouches, they make a nice addition to the pack for your frequently used items.
Mine fits great and is very comfortable. I've had weight in it and hiked a few times.
I went with the 1850 as I was looking more for a dedicated day pack with the ability to still pack meat. The 1850 has the perfect amount of room for a full day hunt, plus some.
I'm sure you'll enjoy yours!