Training & Nutrition - Powertap Comparison Questions

I was thinking about getting a Powertap - but had a couple of questions.

For reference, here's cycleops' comparison guide: http://www.cycleops.com/products/powertapslcomparison.htm

1. Cycleop's says that the base Powertap has 'Cadence Measured by Hub' capability, but not 'Cadence Measured by sensor' capability. Huh? Does the Powertap know what gear I'm in?

2. Can I use a general polar heart rate monitor chest strap, or do I have to use the cycleops strap? I ask because I was thinking about buying a used Powertap... and using a HRM with a couple thousand of hour's worth of someone else's sweat... well, doesn't sound appealing to me, even after being washed.

3. Anyone use the 'customizable' display on the Powertap Pro? Is the Pro worth the price difference?

Thanks!

I'd be interested in knowing the answer to these as well.

I had no idea my display was customizable, i'll have to look at the manual when i get home.

I use the customizable display on my SL. It comes in handy when I want to be able to view my wattage, cadence and hr all at the same time. The downside is when you have it set this way there is no option to view speed.

1. Cycleop's says that the base Powertap has 'Cadence Measured by Hub' capability, but not 'Cadence Measured by sensor' capability. Huh? Does the Powertap know what gear I'm in?

It doesn't need to know the gear. It calculates cadence by looking at the time between power spikes on each pedal rotation. The instantaneous calculated cadence isn't very accurate and tends to fluctuate a lot, but average cadence over a minute or less is pretty good.

I'd be interested in knowing the answer to these as well.

Since I didn't really get a response here (in a day or so), I posted it again in the road forum...

http://www.bikeforums.net/showthread.php?t=190007

They answer some questions/give some opinions there, too.