You know who it didn't flatter? Ben Spies. He won a race on it but thats about it.
Ha! F-ing Spies, I still think he got a .... shake in GP bro. I feel he didn't realize his true potential, which I believe was considerable. Really underrated! He did very well for Tech3 and when he was promoted to the factory squad, from the get go it aways seemed tentative.
Ok ok, let me try and make a case for Spies since we watched him grow up in AMA. Just for the hell of it. Hear me out. (Believe me, it's a curse bro.) But...
1 win that is correct, the same win total that the great Rossi had when he returned from Ducati. So we could say, you know who the M1 didn't flatter on his retun, Valentino Rossi. Crazy right? The Greatest of all Time and Ben Spies got the same win total in a year's worth of Factory M1. This was Ben's first year ever on a factory Yamaha. Btw, should have been two wins but he got nipped at the line by Stoner on the RCV rocketship at Valencia. Ok, so like Steeeve said, "if" his aunt had a .... she'd be Kaytlin. As much as there is truth to that, there is also wisdom in digging a bit deeper for meaning. Otherwise, we could look at Hulk Hogan's world title and based on "results" conclude, well that mofo is the greatest wrestler of all time. Interesting enough, both Spies and Rossi notched their single win at Assen. However, let me add a bit of circumstance, Lorenzo had just won the previous two races and looked good to win his 3rd at Assen. But he broke his Pedrosa bone during practice. He still raced (after getting surgery between practices) but came in 5th. Rossi won. So even that 1 Rossi win was circumstantial, in weather, otherwise it likely should have been zero wins on a factory M1.
So Ben looked good going into that next season. Almost 2 wins, double of what Rossi got after only being off an M1 for two years. And God knows Rossi was fresh as a daisy when he returned, as it didn't look like he risked .... the entire second year at Ducati, unlike Spies who had been killing himself in hopes of getting promoted. While Spies was tearing himself up for the factory ride, Rossi was putting in a call to his sport agent Carmelo Clause.
Well...so what happened Ben's second year at Yamaha? Oh yeah the team looked busy creating an extraordinary and seemingly unbelievable number of mechanicals and mishaps. One could say it killed all confidence for Spies, and as they say, racing is lots in the mind, confidence being probably the most important. I honestly can't remember any factory squad having so much .... happen. I'm laughing remembering his swingarm going cottage cheese.
How many races did Rossi win in his second year on an M1? Answer: 2. Both wins when Marquez crashed out of the lead! So in a two year span Rossi, the greatest ever won 3 races (all 3 with from attrition) , Spies 1 (almost 2). You got to wonder out of half a season of mind-boggling mechanicals, maybe one or two might have resulted in a win? For perspective, Ben's swingarm cracked in half down the Corkscrew. A ....... swingarm! Haha. Jesus. So over a two year span, I can't really say the M1 flattered Rossi all that much better than Spies. Another conclusion can be, Spies was nearly as good as Rossi on a factory M1. Much has to do with intangibles and circumstances, that's just how it is, aunts with dicks.
So, I'm sticking to JKnock's assertion: the next move for an "alien" is a factory Honda / Yamaha, but with one little caveat, that the guy needs to be supported like a GOAT.