I have done plenty of both, no preference but man I screen the people I go to Disney with. I was very disappointed once by someone who wanted to go, loved all the rides, HAD been there before but when we got there, just about every ride was "I'm not going on that!" "I'll get sick!" "You're not getting me on that!" If we didn't have so much fun on the rest of the trip I would call it a waste. But she was cool in that she stood in the line ups with me, just when it came time to get on the ride, they let her stand by the dis-embark 'til I came back. (We called it the chicken-bleep door). From now on, I'm going to specify - do you like roller coasters, do you like dropping from the sky etc. Taking my niece for her high school grad was a blast, too. I like taking someone for the first time, seeing it with the fresh eyes that were mine on my first trip in 1986.
I've never gone with a big group. It sounds like when big groups go and they insist upon sticking together, they spend all of their time rounding everyone up.