The 1450 has all the latest technology (maybe good, maybe bad...depending on you perspective) and the removal corner panels for easy cleaning. The E1400 does not have that. I had inquired with my CB dealer asking if they, CB had a retro kit available to make the corners removable on the E1400 and he said not yet. That tells me they are maybe working on something. That being said, I love my E1400. This is my 3rd year with it and I have had no trouble with it other than the self-imposed problems. I got lazy and neglected to clean the air holes in the firebox for over a month. Guess what happens, they clog. I clean the air holes every 2 weeks and empty reaction at the same time. It takes me approx. 30 to 40 minutes from start to rekindling the fire. I do it at 6:00 in the morning so by 7:00am I'm back indoors having a second cup of coffee and have the full day to get other things done. The only thing that's proprietary on the CB E1400 unit is the electronic controller. Everything else (Blower, solenoids, replacement cartridges for the Taco pump, etc...) I can get at a good HVAC store in a neighboring town. I haven't had to change them yet, but I know they have them. I know nothing of the P&M units other than they sound like a good unit. I read a lot of praise from people who own them. But I cannot comment on them due to never having operated one. Good luck! Roger