I have used the Great Value
powder, and it does work well, but I have differences of opinion with Wal*Mart's corporate philosophies, et cetera, so I try not to shop there.
I usually use Cascade Pure Rinse powder. Friends have given me other brands of detergent, and I am just finishing some Electrasol gelpacks, which have also worked well.
In my years of automatic dishwashing, I have had minimal etching, mostly because Kent's water is on the bare edge of hard (maybe 3-4 grains).
My glassware is fine, for the most part. I've had more etching on Pyrex than on beverageware.
And, I only scrape, never ever pre-rinse.
Lawrence/Maytagbear