>Does anyone have experience with lossy png tools?

I do. Lossy PNGs work great for images with not a lot of colors. I use pngquant and optipng a lot in my work to compress a lot of PNG images with practically no visual quality loss.

For very colorful images, lossy (quantized & dithered) PNGs just don't work, though. They just end up looking nasty with larger filesizes than what high quality JPG gives you.