I'm a few mixes away from dumping my iLok and going further into UAD. As a fellow Logic user, if I were on one card, I'd go Neve 88rs & LA2A at the bare minimum. Another one worth consideration is the VCA VU is a super light dsp hit and a great comp.
I would like to ditch every one of my native plugs (except the Maserati and Abbey Road) for more UAD, and I've got the Waves SSL and demoed the Waves API. The mix seems to open up and retain its three dimensional qualities when I pull off the Waves and throw on the UAD.