"I'm getting ready to do a job where I really wish the customer went with the 325G but yet wanted to stick with the smaller 250. "
He may want to reconsider? He'll make more trips to fill it and won’t get the gasification benefit. I am very surprised at the amount of wood I am going through (very little, 4 TO 5 24" x30" oak rounds per day, split 4 ways. Fill once in the morning before I leave for work and once at night when I get home. Mid teens at night and mid 20s during the day!)! Also with the 325 capacity the boiler can stand several cycles of the furnace with out kicking on the boiler blower.
I'm pretty sure it will still work on a 12 hour schedule. Temps here the past few days have been single digits at night and 18-21 during the day, it's a heat wave today and we're up to 25. haha
He has access to plenty of top quality firewood! If he burns good seasoned oak, hickory, etc. He'll be good.
I have my 175 heating 2200 sq ft and water, and last night it was 6 degrees and I still had wood in the firebox this morning.