I own the LCD deck and goofed off with the OLED deck. The screen is perfect, just like I imagined. But the thing that caught me off guard was how much lighter it feels. They say it's 30% or something lighter, but because of the way that you typically hold it, it feels half the weight. The joysticks also have a deep recess on the inside, which makes your thumbs slip a lot less.
Overall, I would say that if you currently have a Deck and play it every day, if you can sell your old one for a reasonable price, the cost is probably worth it. If you're a casual gamer and you only play every so often, the upgrades on the new Deck are great to have but probably not worth the cost. As a new purchase, OLED without question.