I believe that the Trac II or GII in Europe is perhaps the greatest shaving implement Gillette still sells. I get irritation free BBS two pass shaves everytime. I use the original plastic and metal handle, but i have been thinking about upgrading
I have never tried the the trac II as I am a bit young but I do remember liking the sensor excel quite a bit when I was a teen but back then I didn't have near the facial hair I do today and I was suckered in to all of the different mach3s and fusions and sheik hydros and such so I haven't revisited the sensors but reading some of these post makes me want to try some of the older cart systems as a back up to my DE razors in the event I do need to do some air travel or something.
I believe you can still buy the Sensor on Amazon for a good price.
You have to be careful not to buy the newer thick handled razor which is a piece of junk and get the old original thin Gillette Sensor Excel handle. I bought a second one for a spare from South Korea on Ebay.