It may well be that your older ones are ready to move on to high school level work with more management falling on their shoulders. I know that sometimes it looks like they can't handle more responsibility when they complain about what they already have, but kids can be funny that way.
Most young people begin to thrive more on structure, research, and application during the late jr.
Their thinking will be far more challenged. You had mentioned wanting to see a love for learning in your children. You may see it in unexpected ways. We moms sometimes confuse the natural human tendancy to resist work with a lack of love for learning. Most athletes I've known don't enjoy the daily pounding they must give their bodies to stay fit for the race or game, but they love what they do in the big picture.