I'd take Felix in a heartbeat. Fantastic player who is absolutely wasted at Atletico.
He's different then anything else we have up front, and I think we're soon to be a bit thinner there then we look on paper.
Sterling and Jesus might both be out the door this summer, and if not this year than almost certainly next in Sterling's case. I'd expect 1 of Grealish or Foden to play in midfield sooner rather then later. Alvarez is all potential at this stage, and I wouldn't expect much - anything we get from him in year 1 is an absolute bonus. Mahrez is aging and out of contract soon. Palmer is unproven.
If there's a deal to be done, get him in.