Sabo sweet spot: you can keep alive your blockers ( Sabo5 , Hina5 , Borsalino4 ) each turn for free with leader ability or maintain your Kuzan4 to put pressure and have good Rob Lucci4
You also get two foil Floodborn characters, The Queen, Commanding Presence and Gaston, Intellectual Powerhouse, as well as some shift targets and a couple of support cards in Grand Duke and Lefou respectively
Same for enchantments
Mirage and especially Visions were incredibly good at being fun to draft, having powerful commons, and bringing out some fun cards and mechanics that are essential to the game today
Yes, commander tax applies individually to partner with commanders
Every time one of your merfolk hits an opponent, you get to draw a card