From having the Tour Ultras and now having the SST 8's I can say that they are both a very quality shoe.
The Tour Ultras lasted a good 2+ years for me before needing replaced. When I replaced them I got the new dexters and like them better, its just a feel issue but they are a little wider and feel more supportive, while this adds weight to the shoe is the downfall.
The TU's are a great lightweight shoe but i personally just like the feel of the SST 8's, personally I don't think you can go wrong with either option.