There are three major global alliances — Star Alliance, SkyTeam, and oneworld. In general I’d say that Star Alliance has the best collection of airlines, while oneworld has the most valuable reciprocal elite perks. Meanwhile SkyTeam is sort of just the alliance of leftovers.
Overall I’d say SkyTeam airlines are improving, as they’re largely refreshing their longhaul fleets with fully flat business class seats. Still, I don’t think SkyTeam has historically done much in the way of innovation.
However, SkyTeam has just announced a very cool new functionality that we haven’t seen before. SkyTeam has introduced an online retroactive mileage credit tool that works in real-time to validate retroactive mileage requests, giving you your missing miles instantly. Per the press release: