Product review (2 stars): Hack to use any water filter with RPWFE refrigerator
Like others, I find the price of the RPWFE to be too high, considering it gives no advantage over the RPWF. I have done some experimentation with the RFID system and here are my findings thus far:

 - The chip has no connection to any sensor in the filter and is simply taped to the outside.  This means that it does not perform any sort of diagnostic function for the filter... unless it has some sort of miniature x-ray device built into it...
 - The RFID chip on the "E" series of filters appears to serve no function other than a form of DRM to prevent other vendors from selling filters for GE fridges.
 - The tag appears uniquely identify the filter as the refrigerator can tell if you simply remove and reinstall the same filter.  A soft restart of the refrigerator (powering down the fridge for 10 minutes) does not appear to clear the refrigerator's memory of a particular filter ID.  A factory reset of some sort might work.
 - You can remove the RFID chip from the filer bypass cartridge that came with the refrigerator - it is under the red "BACK" sticker.  Attaching this chip to any filter that fits (RPWF) will get rid of the big red warning message on the display.  It will however put up a message saying "not filtering" every time you dispense.
 - The bypass cartridge chip does not affect the filtering action of the fridge.  Water will still be filtered, even though the message says it is not.

It would be interesting to see if someone with more experience with RFID has had a chance to read the tag on the filter to see what it is reporting and whether there is any sort of encryption being used, otherwise, you could probably code your own RFIDs and use them on cheaper filters.  All in all, way to much work GE, just so you can make a couple extra bucks on filters :-(