We just re-watched the first one the other day, and I gotta say, I like the second one better. I feel like the Star Wars / Empire comparison is very apt in this case.
GOTG was fun, exciting, different and vibrant. It really opened up this world (or corner of the MCU) to us viewers, gave us something new and it was amazing!
GOTGv2 effectively built upon that world, taking us to new places and bigger effects. But more importantly, it was a more emotional story, where we really got into the heads of our characters. They became rich, 3 dimensional people, rather than a checklist group of heroes.
Is everything in 2 better? No. I prefer the soundtrack to Vol1, and I also agree that some of the humor was a bit over the top. The space battles in Vol 1 seemed to have much higher stakes.
What shocked me on re-watching the original was how simple the characters were by comparison. Rocket, in particular, was very much: "Hey look, a raccoon with a gun! Who's quippy! You've never seen that before!" Whereas in Vol 2, his raccoon-ness wasn't even an issue. He was just a good character, with some great interplay with Yondu.
... well, ok. Scampering across the Ravagers' heads & in the trees wouldn't have been nearly as awesome if he weren't a raccoon.