x-stop surgery

I am reposting this question since I mistakenly listed my user name instead of the subject name previously and apparently will not receive any feedback without that subject.  
I am a 59 yo male contemplating either this relatively new type of surgery which uses a titanium spacer in what is referred to as IPD, Interspinous Process Decompression, or x-stop.  Also my doctor mentioned an alternative which employees the use of screws into the vertebra body,(?) and tough plastic tubing as a spacer which is all connected with rope thru the tubing attached to the screws above and below the  area of decompression.  Can anyone related any experiences, pro or con, with either type surgery?  Apparently the basic principle is to wedge the vertebra apart in order to open up the space and thus provide more room for the nerve roots to exit, etc.