I *love* Pureology; it's all I've used since it was introduced. The hydrate shampoo and conditioner really help hold on to color and leave your hair silky smooth. The only other shampoo I'll use is Artec white violet (on the 2nd shampoo) as a supplement. I hate how the Artc makes my hair feel, but it's the best stuff on the market for keeping highlights bright. Finishing with the Pureology conditioner smoothes everything out after the Artec.
My hair grows really fast, so I have color (highlights and lowlights) and a trim every 5 weeks simply because my regrowth is nearly an inch by then. Additionally, I've trained my hair to stay clean looking for 5-7 days between washings, so on top of the help from Pureology, the reduced shampooing leaves my color looking as fresh as possible in between visits. Just don't look at my roots on week 5! :)
I absolutely cannot stand the fragrance of Pureology products. I haven't notice an allergic reaction (I am allergic to lavendar) but I can't stand the smell. My hairdresser recently changed salons to one that uses these products and even though she doesn't use them on my hair, the smell still bothers me--I may have to find a new hairdresser soon.
They may be good products, but I stay away from them.
I love their products! But I definitely smell the lavendar, so I could see it causing a reaction if you are allergic. The only problem I have is that they are a bit hard to find in LA - at least in my neighborhood!