Personally, I love mine! Then again, although every person is different, the type of jiggle balls you get (the size of the balls and the weights of the inner balls) can affect pleasure sensations aswell.
I don't use mine for kegal exercises as I'm fairly tight anyway, but I use them for a bit of pleasure.
I enjoy going out for a walk in them or doing household work as the way that I move triggers the movements of the weighted balls. If they're positioned correctly they also tap against my G-spot which is extra pleasureable!
Don't give up on them yet though, try keeping them in for 30 minutes at first then gradually keeping them in longer with each use as your body gets used to them. You might start to enjoy them more. :) x