Congratulations on buying a Tiffin and welcome to the Tiffin Family.
As others have said make sure that you check everything out before you leave the dealer's lot. Just because it is listed on the invoice doesn't mean it is there. Ours was missing the Tru-Center steering and the heat pump for the front AC unit. We also found the electric side of the hot water heater wasn't working due to it not being plugged in at the water heater. A few have found that the ice maker doesn't work but that is usually due to the water valve being turned off.
You don't need to buy an extended warranty when you buy the coach due to everything will be covered under it's own warranty for at least the first year. Tiffin does have the reputation of standing behind their coaches even after the normal warranty has expired but you might have to take it back to their factory at Red Bay, AL. (CRB)
Check out the Tiffin RV Network for all the information you need.
Tiffin RV Network
Jon