Williams would be a pretty good seat for an up-and-comer. They're not a top team, but they're good enough for top 5 finishes and the occasional shot at a podium. Bottas has overstayed his welcome and needs a top drive (replace Kimi), otherwise he'll stagnate. As much as I'd like to see Vandoorne in a race-winning team from the off, it won't happen...Williams would be perfect (as long as they don't go backwards next year).