"Am I correct in understanding you to say that the 3-D is more trickable, but requires a lot more movement and attention as a result?
Could I also trouble you to help me understand "efficiency" as it applies to indoor flying?"
Yes, but not necessarily a lot more movement. Part of the extra work is keeping the kite in motion. Finding that point where you give it just enough energy, and not waste any extra energy, is the efficiency I was talking about.
A Wren is an easier kite to fly indoors because it's more forgiving. It's also nice and slow, graceful , and floaty. It actually takes less energy to keep it in the air. It's harder to do a fast axle or 540 on a Wren rather than the slow tricks that it likes. It's so light and flimsy that you'll likely just jerk it out of the air, instead of getting that real fast trick. With the smaller stiffer indoor kites like the 3-D you'll get the quick tricks but it's harder to get the slow stuff. I really enjoy getting a slow low 540 with my indoor Pizazz that would rather be moving quicker, like the 3-D. Of course, I love the incredibly fast tricks with it, too. There really are so many different indoor flying styles. Each kite has it's strengths, or things that it likes to do. Each flyer develops a style or styles,(If you are really good). I think it's important to find that connection, but it can only be done by spending the time flying.
Hope this helps, but if not, I don't mind rambling on.