Thanks for your feedback Pointblank!
I really am impressed with the design of the 550, as it kinda follows the KISS slogan.
I'd be real tempted to buy one if I didn't have a spare P&M Optmizer 250 on hand as we speak.
Central Boiler has this unit priced where it should sell like mad.
I am really looking forward to my friend getting his up and running. As far as gassers go, Portage and Main are the most popular in this area.
I've seen CB's 1400 and 2300 in operation, and I think your 550 will not be anywhere as finicky to operate as they are.
A few more questions for ya, if ya don't mind.
What king of heat load are you putting on your boiler? (sq.ft.,insulated well?)
How much less wood does it consume than your old ripple top? (50% less?)
If you fill it completely, will it last 24 hours?