I've had the 6000 job for a couple of seasons.  It works fine.  My burn times are all over the place, depending on the wood and temps out side.  I burn junk, rotted and dead wood.  Mostly dead, rotted cherry and dead, rotted poplar.  I have a lot of it.   That stuff burns quick, like about 8 hour quick.  At about 0 to 10 degrees outside.  Now dead and rotted oak, beach and locust,  which I don't have a lot of,  the burn time seems to be about 12-15 hour per load.   My loads seem to take up about 60-75% of the firebox.   What I do not like about my boiler:   The paint lob on mine is crappy.    Like some spots with  a complete lack of paint.  So I touched it up.  Wiring is a joke, but very simple.    I built a shed around mine, which I planned from the get-go , to keep the boiler and log splitter out of the weather.   But as I said, it works ok.   The damper flapper door needs to be lubed with WD40  from time to time, about once every 2-3 weeks,  so that it does not hang open a fraction of an inch.   If it hangs open a bit, it'll run hot.   One fellow on here, mremm,  has a Ridgewood stove but has had some trouble with his running  hot.  I don't know if his ever got sorted out.     Oh well, good luck