I played a big chunk of 3, and this might sound dumb, but I found the switching between three captains to be overwhelming. I just wanted to control one and stick to managing the Pikmin. I loved the demo of 4 and think it fixes most of what I was bouncing off of with 3. Would I like 1 & 2 though?
2 adds Louie but switching isn't nearly as important as in 3 and can mostly be ignored. There are some bosses that were designed with splitting up and switching in mind but they're not impossible without switching.
If you enjoyed the demo of 4 then you should give 1 and 2 a try, especially 2.