We have an 08' BH3670 and love it. Other than a problem with the "black tank vacuum breaker check valve" being totally hidden and dumping water into the interior of a wall, we've had very little problems at all with our RV. Believe in 09' this VBC valve is located behind the shower circular inspection port and at least you can get at it.
Thanks for all the info. I am now thinking of buying a 2008 F350 (diesel). Any thoughts, comments on this being suitable to pull the 3670RL, please advise. Not sure of all the specs on the truck, other than F350, diesel, crew cab, standard size bed. Thanks again...