I've had mine a couple years now.
Overall it's ok. It's a cheap power meter, so you get what you pay for. There are a lot of wires, and many parts are cheap plastic. I guess that keeps the grams low, but it doesn'tt inspire me.
The computer functions are good. There are other software options on the internet which I found to be better (http://www.cyclingpeakssoftware.com
The accuracy is better then I expected, similar to the power tap. Peak power is difficult to acquire due to slow acquisition time.
Best feature is the Cadence, HR, Power screen. And cost is reasonable (as for as power meters go) Although they are all over priced if you ask me.
Worst feature is the array of sensors one needs to setup, if one gets out of whack it'll stop working. The cadence and power are built into one part which is a pain to adjust vertically and laterially.
Would I buy it again, maybe. I think I'd be tempted to test out the Power Tap pro coming out this winter, which is supposed to be totally wireless and better for peak power measurements. But I'm sure it'll be at twice the cost.
I don;t know about LizardSkins, but I wrapped my unit with 4-5 layers of electrical tape. Works good for me. The black hides the dirty chain marks.
I've had no problems with hitting the sensor with my foot. I can;t even imagine how someone could hit it... unless you had a crazy chain line, duck-toed feet, or something weird. The sensor should not go beyond the chain in the last cog, so if you're hitting the sensor, then you're likely hitting the chain with your foot also... that's very odd.
I do periodically have to play with the sensors, but it's not such a chore that I'd not use it. The data it provides for the cost is worth it.
The big thing I get from my power meter is a percieved exertion vs. actually exertion. Hard to do that w/o a power meter.