Buddy found this.Not bad, since it comes with free wideband. Only $100 or so more than Aeroforce, and it seems to have more parameters, and can view more at once.

http://www.plxdevices.com/products/dm200obd/

I don't see a KR readout? I see it monitors 2 knock sensors but what about KR? That's the main thing. How many degrees of timing is being pulled?

I think it reports approximately the same information. In the PCM, the knock sensors get filtered (analog on the 97, digital on the 98+) and then the PCM determines the level of severity, then uses a table to compute how much timing to pull and how fast to pull it and let it recover.

Anyway, sweet looking gauge, but the pricing situation looks like this:
Aeroforce $230
PLX $400
quite a different.... and I don't see the free wideband (?)

If I had the choice between the 2 aeroforces or one PLX, as long as the PLX did have a KR readings, I would have gotten that one.