I started with World, and put hundreds of hours into that and Rise, plus their expansions. I tried the GU demo on Switch, but it felt too clunky.
The thing that hooked me was the first large monster you hunt, Great Jagras. He's a pushover for any hunter with even a slight amount of experience, but for me as a new player, it was an epic battle and I certainly didn't expect that much intensity that early in the game. I also liked how even after you had a monster on "farm status" a hunt could still easily go from good to bad if you weren't careful. It emphasized that these monsters were incredibly dangerous, and even seasoned hunters could be in trouble if they get too cocky. It also helped keep farming more interesting as you needed to pay attention if you wanted to be successful.
Overall, I like the... world, in World more, but the gameplay mechanics and combat more in Rise. In World, the maps were larger, with more detail and felt more alive. I also liked the tracking aspect, and was disappointed that aspect didn't make it to Rise. It felt like you were actually hunting your target, instead of just sprinting to their location on your doggo friend and beating them up like in Rise.
I'm definitely looking forward to Wilds releasing next year.