02 Sensors - Porsche vs. OEM vs. Replacement

[smartguys]

All you mechanics, speak up please. As you know, 02 Sensors are priced all over the map. From $25 to $225. What's odd, is that the $25 eBay replacement Sensors look identical to the original Porsche Sensors. Now yes, there was the splicing wires issue, but I'm wondering if these cheap Sensors are really all that bad? Meaning, are they as bad as the ultra low $25 makes them feel like they might be? They looked identical when I removed the originals. I only replaced two thus far, but am fearing the "you get what you pay for" syndrome. Any advice?

here are the $25 cheap eBay Sensors:

http://cgi.ebay.com/ebaymotors/O2-OXYGEN-SENSOR-BECK-ARNLEY-SG1101-PORSCHE-BOXSTER-H6_W0QQcmdZViewItemQQcategoryZ33557QQihZ020QQitemZ 300237293114QQrdZ1QQsspagenameZWDVW