FYI, I was the one who enjoyed a Bike Barn that collapsed due to snow. :banghead:
I've had a barn since 2011. Same aluminum frame, but I bought a replacement cover in 2015. I found that my first cover got brittle over time in the sunlight (read: easy to poke holes through, but you can patch with tent repair kit), plus it gets a little ganky (is that a word?) on the outside with dirt/mold/etc.
That said, it's still the easiest and fastest way to cover the Spyder in a driveway-- lift it up, pull it down, easy-peasy. Plus, even with Spyder parked there's still room under the barn, so I've kept a little plastic garden box with miscellaneous items, cleaning materials, my bike lift, etc.
RE: the "heater" sold by Bike Barn-- that's just for dehumidification, it won't warm the actual Barn at all. I had that heater for years, but eventually it died, and I've simply gone without it since, and haven't noticed any issues *inside* the Barn. I just always keep the roof vents velcroed open, everything stays fine under it. If you want to put a space heater under there in the winter, YMMV.
Bottom line: it's well worth the price, but it'll never be as good as an actual garage, so manage your expectations accordingly!