Regarding V10 noise. We just purchased a used Tiffin. Engine noise was one of the many pleasant surprises. Yes, I wish it were quieter or non-existent, but it is not as bad as I'd heard in other manufacturers. I don't know if Tiffin does additional insulation or not, but the noise, IMO can be tolerated.
I've only owned travel trailers prior. Their quality is mostly unacceptable, but we buy them because they are the only option (aside from a few high end manufacturers). When shopping Class A's, we wanted a step up in quality, unfortunately, many of them felt like a trailer on a different platform. We never allowed ourselves to shop Tiffin/Newmar, due to our budget. However, once we opened our minds to it, we started to become satisfied in build quality. You'd like to think that at these prices, Tiffin/Newmar would be the starting point of quality instead, but that isn't the case.