I have only been in a Costco once or twice, but I agree with you, Earlene -- I like it better than Sam's Club. I don't have any clue if they treat their employees better than the Walton empire does, but Costco products are more interesting and useful to me.
Costco really does treat their employees much better - they pay them better, their benefits are better, more full time employees, and it's just a better environment.
My sister has worked for Walmart for years. Things have changed since Sam Walton died. When he was in control, the employees were well treated. They even had the option of buying stock in Walmart.
Not sure what they were like before Sam Walton died (or when he died) - my sister has worked for Sam's for 15 years, and has just surpassed the $15 an hour mark. Barely got offered benefits (full time) 5 years ago, and has been denied management positions several times even though she has a business degree in management.
Their bonus' are directly related to the particular store they work in, and the profit/loss margins that particular store has.
My nephew (her son) worked at that same Sam's for about 6 months, quit, went to work at Costco in the same department (meat dept.) and he said it's like night and day - the pay, benefits, atmosphere, and just general respect from the management team are (in his words) "a billion times better"
Maybe my sisters experience is unique to this particular store/area, but IMO, with everything I've seen, heard and read, Sam's is not a great place to be an employee at.