And to follow up on what Qotsa said, X/Y is best only when you have done none of it in the previous year (Resets yearly at 0000 01Jan). As soon as you start getting some premium credit under your belt, you move further down the list and are less likely to be called (unless you're somehow the only person on the list).

Also, choosing to Y list out of a destination rather than a base isn't going to yield you too much since you're basically banking on things like weather, meltdowns, fatigue calls, etc (the uncommon things) in order to get that call. If that's your plan, don't set yourself up for failure by expecting calls just because it's a heavily serviced city. Making plans based on X/Y has always been a gamble, Destination Y only would be really tough to plan around if you want extra money.