Congrats on the New-to-you coach. I share your like for this floor plan.
Yes, They are helpful in all of my dealings with them. They are a one-stop parts supplier for many owners; but many common MH items can be purchased for less online or, via bulk suppliers.
Be sure to register your VIN with both Tiffin and your chassis manufacturer. Your engine and tranny resources are here with advice on best filter, fluid, service tips, etc.
Also, worth mentioning is to keep an electronic file of service tips that you encounter on these forums. It comes in handy when you're stressed and have no beginning point for diagnostics of a problem [perhaps well-discussed in past posts with pics, procedures, short-cuts, etc.]
Please join us on this Forum as well: Tiffin RV Network