We had previous trailers and 5th wheels with a rubber roof. There's nothing wrong with them and they will last a long time if properly taken care of - mainly, keeping them clean. Dirt will deteriorate them fast. We've never had leaks or problems with them.
Also, you'll have to be careful about scrapping tree branches across the roof when pulling into campgrounds. They will tear.
Entry level RVs?? Sometimes that can be good, especially for first-timers. Most use their first one as a try-out. Sometimes they find they don't even like RVing but most often they find after using it for a while that they want a bigger one (or a smaller one) or more features or a different kind, etc. With an entry one you're not out of a lot of money if and when you want to change.
Consider buying a good used unit from recent years. By doing this you'll be able to better afford a unit that's not considered an entry one but still pay a new entry RV price. There are many excellent used ones out there. Good luck!