I can't speak for the 29BHS but, but as far as the 25BHS the differences seem to be in the wiring or pilot setup. I have a 10 and my buddy has the 08. If I remember right, the only differences may have been automatic lighting on pilots on the newer model. I would ask about that for sure. We love that everything is push button as far as lighting the furnace / water heater. It also switches the water heater from gas to elec with a switch as well on the 10. The refrigerator is also all automatic. Only calls for a flip of a switch to operate in either gas or elec.
I would also check the model of converter. 10 has a Progressive Dynamics 45AMP converter that is supposed to have an extra level of charge to maintain battery during longer charging periods. Not sure if the 08 has that.
The exterior and interior seem pretty identical however. Those G2s are nice.
2010 Jayflight 25BHS
2003 Chevrolet Silverado 1500HD 6.0L
V-5 Talon hitch
Valley 1200 WD hitch w/ Valley sway