I've taken to zwift ever since I figured out how to run it on my ipad with a 4iiii heart monitor to hook up my old stuff... then I went ahead and got a kickr so I'm doing about half my regular riding on it... brutally honest with the weight/height and it seems to be comparable work to riding outside... my time up Alpe du Zwift was pretty close to my time up Whiteface Mountain, which is similar to Alpe D'Huez. Longest ride so far was the Über Pretzel, took me around 6 hours of riding... I took a few breaks but kept them shorter than I would in person since it's pretty easy to eat real food and ride a trainer.
There's heaps of people with poorly calibrated trainers and outright cheaters but it's not like they are fooling anyone but themselves, if someone wants to run their bike with an electric drill to "win" a virtual challenge badge that's fine by me. I think if the zwift stuff brings folks into the rando fold that's cool. I hope to try a 200km on zwift at some point, there are occasionally organized longer distance rides and they are easy to crank out on the flat courses in big groups. The zpower website does a good job of catching outliers and it seems that's where the more serious folks go for standings and whatnot.
I am going to try and ride what would have been this year's first ride in my town, but going to have gear up like I'm riding a 600 with the extra supplies I'll bring so I can't just kind of plug along without stopping for a sit-down meal. I have also thought about doing urban laps since there is so little traffic on the secondary streets in my town now it would be kind of fun.