Looks like the Mauricio/McNeil combo will allow the Mets to have a lot of positional flexibility in the near future. The Mets now have options next season at various positions. I'm changing my mind on Alonso - I think the Mets are probably better off signing him long term, and not spend big money on an outfielder. They can cobble an outfield together in the near term, and they've got a whole group of versatile, athletic players coming up who are showing right now in AA that they'll be ready sooner rather than later. Gilbert is likely to be ready first, but Acuna isn't far behind. Jett Williams is closing the gap faster than anyone thought he would. I don't know if it's going to create the best offense (a McNeil-Nimmo-Marte-Gilbert + mixed outfield will have well below average power), but I really enjoy watching athletic teams who run the bases as I guess is normal for Mets fans who grew up in the 80s. I think that's one of the reasons why I'm not as high on Baty & Vientos, neither of whom fit that bill.
I love Mauricio at 3B. I like his arm, I like his hands, I like his baserunning ability, I like his energy, I think his bat is fast enough for him to adjust to MLB pitching, and I think he has more than enough power to hit 20-30 HR.