Like you mentioned the perk is you get the department store discount, and naturally you can only use your staff card at a free standing store. Now Store vs. Pro store. Since I've worked at both let me tell you the pay rate $25 is innacurate. I cannot post how much I am paid, but it is not that.
Lancome, Dior and other brands pay their freelancers that much, BUT they don't have nearly as many hours as MAC gives its freelancers.
Working at Pro, I absolutly loved the products. You get to experience 100% of the MAC cosmetics line. There is definetly higher skill expectation, and you learn so much from being around seasoned artist. The norm is working counter, store than Pro. You should be certified in most if not all areas. And I say the "norm" because I was hired straight from the freelance team on to Pro.
I currently work at a freestanding store because to meet the needs of the business Pro and other locations had layoffs, my job was one of those they cut. One became available at my current location and I jumped at the chance. I love it! I miss pro product, but other than that there is no difference.
I get my same pay rate as when I left pro. here we have about 90% of th entire line. Other than that honestly there is no diffence. The discount is the same no matter where you work, same benefits and such.
Good luck!