Copied from my thread.
The PB Pro Series 1100 is new, but the PB Austin XL and the PB 1100 Pro Series are almost exactly the same grill. Researching the PB Austin XL will help you get up to speed with PB Pro Series Grills...
Other than the 1100 sq inches of cooking area vs 1000 on the XL, The big differences are mostly cosmetic. To the best of my memory and in no particular order:
1) The PB1100 has a different style, slightly larger side tray, but the tray on the XL is removable and can act like a serving tray, I think.
2) The PB1100 has a 35lb hopper vs the XLs 31lb
3) The PB1100 has a very sturdy folding shelf across the length of the front. XL does not.
4) Larger upper grill (I guess 100 more sq inches)
5) different style chimney damper
Also the PB1100 has a lever so you can open and close the grate to expose the flame easily.
I also like that the "tool hooks" are on the from of the shelf rather than the side like they are on the XL.
Overall I've been extremely happy with my PB1100. It's my first ever pellet grill, so I have nothing to compare performance with, but I did spend a lot of time considering the Traeger before I stumbled onto this one, and for me the choice was simple. The Pit Boss has a much longer warranty, and simply looks like it's built much better and of sturdier quality. The Traeger's just looks and feels cheap and flimsy by comparison and over twice as expensive for a similar, but smaller size.