Hey I've worked for a MAC counter at Nordstrom. I wasn't a manager but a part-timer who worked maybe 32 hours a week. You might want to keep the following in mind when choosing:
*At Nordstrom you will have to/are encouraged to cross-sell (your line and others, and even sell fragrances and clothing) vs. MAC store where you only work with one cosmetic line.
*Department store atmosphere vs. cool MAC store atmosphere.
*Two words: Rewards Card. At Nordstrom, you will have a goal each month to open these cards. At MAC you don't have to worry about this.
*MAC: You have IPT (Item Per Transaction) goals that are pretty important.
*MAC: If you are more into makeup art, this is where you want to be. Lots of makeup appointments, so lots of chances to do makeup.
*At the Nordstrom I worked at, the Trish counter was very slow...less sales.
*At Nordstrom we had to sell over the phone. At the MAC store you might have to do this too though.
*At MAC you can dress funky (yet in black) vs. working for other lines who might make you wear a lab coat or not very attractive uniform.