TN Tracker,
I looked at the Cooper STT. They don't come in a 235. 
They are doing away with the old style STT and replacing it with the S/T. At least that's what my Cooper dealer told me.
Keith,
I had a set of Dueller Revo's, good tire. A little expensive!
Cwkick
Cooper has caused a little confusion with their names. The STT is available as a 30X9.50R15LT, it is an off-road designed tire and that size works out to a 29.70X7.80

The Radial STT is available as a LT235/75R15 and that size is actually a 28.90X6.90.

The ST is available as a LT235/75R15 which is actually a 28.62X7.20.

All the dimensions were taken from the Cooper Site. Your dealer needs to research his products a little better. They have similar names but are completely different tires with different uses although they are very close in size. I have no idea if they will discontinue the Radial STT but the STT is a new product.