Tranny flush or no?

I have a 93 Jimmy, that i will be replacing the tranny filter/fluid soon.
Now my question is .. Should I take it in to a transmission shop and have it FLUSHED, or not bother and just do the filter/fluid change in the driveway?
I have heard that flushing older trannys can cause more problems than it cures .. But that was not really from a reliable source.(typical knowitall)
I curently have no problems with the tranny, and I would like to keep it that way.
Any advice will be much apreciated

Thanks
Steve

Not with the machine and I will tell why.When the automatic transmission is flushed with the machine,the machine backflushes with a bad ending.The dirt,crud and metal shavings ends up in the valve body causing sticking valves.I know a transmission shop in my area that does valve body cleaning and rebuilds because of a flush with the machine.Here is a better flush,a line flush and it is better than the machine using less fluid.Remove the bottom line from the radatior,put a hose and point it to a pan.This is the better method than the machine because you can see the condition of the fluid.Start pouring fluid while the vehicle is running making sure you do not run the transmission dry.Get a box of transmission fluid to do this.Stop when it is clear and reconnect the line to the radatior.Changing the fluid and filter a big must also,the filter is just like an oil filter trapping dirt,crud.

I got a thread for tranny filter swap with pics of my '94 Corvette (same tranny) here:
http://forums.corvetteforum.com/showthread.php?t=1845867&highlight=tranny+filter+swap

This topic has been debated pretty well in the past. I pulled these results just from the Chevrolet Avalanche/C&K/Silverado/Suburban/Tahoe forum:http://www.automotiveforums.com/vbulletin/search.php?searchid=2124964 Maybe some of those treads can give you more info also.

It depends on the flush machine. It the machine does the pumping then don't use it. If the machine simply hooks up to the cooler lines and uses the transmissions pump to exchange the fluid then go for it. Flush is bad, exchange is good. With the exchange process there is no chance of causing any problems like debris in the valve body because the fluid is pumped as normal through the filter and out the cooler line and clean fluid returns through the other cooler line.