Barcelona to London: Luton/Wizz, Stansted/Ryanair, or Gatwick/Vueling

I have three options to choose from flying from Barcelona to London. In terms of price (basic fair as shown on google travel, although I will have to add a carryon to hopefully be able to carry a suit), they're almost all the same (Vueling a bit more expensive). They all fly out in the morning so that's not a differentiating factor either. Same with the return trip.

I think Gatwick is a bit closer to London, and it's a simple public transportation to get to High Street Kensington. Luton and Stansted are roughly take 30 minutes longer, and not sure how the transport from there is.

I've never flown with Wizz. Ryanair and Vueling roughly the same on a 2.5 hour flight, although I prefer Vueling more.

So, which option would you choose?

Thanks