I say bring back the acid water, it's what made islands unique. Personally I think I would have been alright with having all the new features in islands- because right now it just sorta seems like old skyblock but on 1.16. I do like the new spawn, it looks nice and it matches the whole "islands" theme, though I will miss the islands spawn :(
Honestly, the pvp area is kinda a hazard, in the old spawn it was hard to walk straight into pvp, but this new map the pvp area is located near the spawn and I've already walked straight into pvp once and almost did it again a second time, especially after manapond. Though, that might just be me.