I wish they had better looking seals. A lot of them don't look that great. :/ (thunderbolts didn't look nice with Luxray coming out.)
I like the bubbles, though. If you want stars to surround your pokemon in a circle, place them all at the center. Right on that circle. Then when your Pokemon comes out, it will be surrounded by stars.
I don't use them much because I'm constantly changing Pokemon, but I use them in Battle Frontier, because it looks good for the battle video on my vs. recorder.