The console itself is the same size as the V1 Switch iirc, so it still feels comfortable to hold, and it doesn't feel much heavier (if it is at all). The Lite is obv a lot better in that regard, though, and I tend to use it when I'm on the go or in bed or something.
The screen is definitely bigger than the V1, and thus a lot bigger than the Lite, and I like it. It's a little bizarre for me to go from playing Shield on my Lite to playing on the OLED because of the difference in size, but also because the games themselves just look so much... brighter? I'm not good at technical terms but the colors pop a lot more, and I think graphics-wise, the difference is definitely noticeable.
None of the games I play are particularly intensive, though, so I can't say really how performance compares, especially since I've only had it for a couple of days. Still, I really like mine, so far!