I (as I believe many who downloaded at first opportunity) had the same issue. A notification advised there was a potential file issue and that this was entirely fixed by deleting the sim again and redownloading/reinstalling.
Skeptical as I was, I followed the advice and it worked fine. That said, there is a fine semantic line between a 7+ minute load from clicking the shortcut and declaring the darn thing dead in the water.
I I walked to the bar at my favourite watering hole and with an empty bar it took over 7 minutes before the barstaff acknowledged I was there - I think I might reconsider the alternatives - I hear they serve a pretty good pint at "Xbar11".
Odd really because when I heard my preferred bar which to be fair was looking deeply in need of refurbishment was under new management I looked at the proposals and figured 'Xbar11' was going to lose all its regulars. Not so sure now.
I've just written a preliminary review of FS2020 for one of the flying magazines and I have to say it is not the review I might have expected it to be from the early rumours.