Yes, I love the sparklines, bullet graphs, etc. in BonaVista Systems package. I use them frequently.

I suspect the reason why other vendors haven't gotten on the ball is that their...

You've probably already checked out this vendor, but in case you haven't, take a look at:

http://www.bonavistasystems.com/index.html

They were recently acquired by XLCubed, but I beleve their products can still be viewed...