Depends on where you live...as hail is an extremely common occurrence here, Spring through Fall. The way to mitigate around that is to have covered storage. I had reasonably priced covered storage in OR but moving back to CO I found covered storage is a very expensive solution because of the frequency of damaging hail as well as the seasonal snow in this area. It was rare to ever get hail in OR.
So again, depends where one lives what is most important to them.
As to the mention of slides...in the past few years since I stepped foot in an Airsteam TT at a show, I have yet to find any Airstream TT with slides offered including on their own web page. I have heard Airstream did at one time offer a TT with a slide...but not now???
Anyway, best to actually tour an Airstream and draw your own conclusion. I found them to be cramped/crowded with a sterile design to them. Just wasn't appealing to me and my family.