We have a Allegro Open Road 36LA. The only major problem we had was that the dinette material started to disintegrate. Bad choice of materials were used. Took two phone calls to Tiffin to get someone with authority to offer a repair.
Tiffin shipped us a whole new dinette in 2017. Was easy for my son and I to remove the old dinnette and install the new dinette.
That really has been the only major issue. There have also been a recall for the tow hitch.