I have used the personal stylist department several times and I think it can be very valuable. I think the key is to have a good sense of your budget, know the specific items you really need, have enough time set aside to shop, as well as an open mind. I found it extremely valuable to browse the website ahead of time and I loaded up my iPad with pictures of items that caught my eye which I brought with me to the appointment. That way I could flick through the pictures quickly and give him an idea of what I like. When we set the appointment we talked about what I was hoping to accomplish during our appointment. Letting him know I needed to focus on career wear meant he wouldn't waste both of our time by running around and loading up on a bunch of casual items.
It is VERY easy to get caught up on the fun of buying! At least it was for me. Speak up if the items are too spendy - ask if your stylist can think of things that are similar but less expensive. About the open mind....my stylist brought me a jacket that I took one look at and thought, "no way, that's not me" before I tried it on. Turns out it's one of my favorite purchases this season! Part of the fun is having someone bring you items to try on that you might not ever have picked up on your own! Most important, have fun!