In a way you're correct and in a way you're not. Yes, there are only 3 simultaneous effects. But, you can have any amount of those effects on each track. So, if you have reverb on your organ, that doesn't stop you from having reverb on any of the other tracks. You can have any amount of rotary, reverb, and chorus on each track. Plus, you can switch fx throughout the sequence. So if you don't use the rotary organ all the way through the song, you can throw a distortion in during the guitar solo, then move back to rotary when the organ reappears.

I might be mistaken, but I think the JV2080 has more than 3 fx.

It's up to you of course, but I find better quality sounds to be more important than thousands of fx. Also, with clever patch editing you can create some cool fx. I have achieved some pretty convincing chorus, delay, wah, fx by editing patches. This of course is more taxing than just selecting an effect and playing.
In short, you don't get a lot of simultaneous fx with Roland, but there are ways to work within the limits. If you do a lot of ambient stuff, you might prefer the Korg. Again, check on the JV2080, because I think that has more simultaneous fx.