c4c5 - Transmission flush or filter/fluid?

c4c5,

I am looking for advice - after the fact.

At 50,000 miles, I took my 2004 Pontiac GP GT2 3.8 non-supercharged to my Chevrolet dealer for a transmission filter/fluid change and a fuel filter. I purchased the car at the dealer and have done business there for years.

I asked for a transmission filter and fluid change - with Dextron VI fluid. When the car was done and I paid for the service, I checked the invoice. It listed 16 quarts of fluid at $2.75 per quart, a "flush" chemical at $20.00 + labor. I talked to the service advisor and he said they "never" change the filter unless there is a problem. He was evasive about the fluid used and finally admitted it wasn't GM Dextron VI.

My question - I have never had the transmission flush done on a GM car. I have either changed the filter/fluid or had it done at the dealer. Is the flush a good idea? Should I return and have them change the filter? Should only Dextron VI be used? The advisor said they used "Dextron" fluid.

This service was done as routine maintenance - not because I was having a problem.

Thanks in advance.