I use it because I'm basically busy and lazy. I only use the cleanser (but know others with shorter hair who like the styling products) because it cuts down the time in the shower for three reasons: The first is because I don't need to wash my hair every day, whereas using any brand of shampoo & conditioner I can only go 2 days between washes. With Wen I only wash once a week as it doesn't get dirty, greasy or messy as quickly. Secondly, my hair colour fades less quickly so even if the roots come through the lengths' and ends' still looks perfect. Finally, the actual process of cleansing (once a week) is quicker: wet hair, apply enough Wen to coat and massage, leave it pile on my head and wash face and body in shower, massage and rinse, shower finished in 5 minutes if I'm pressed for time.
My only tips are: use the amount they recommend for at least the first time, it seems a lot of product and leads many to say it's too expensive to maintain use long-term. Comb through with a wide-toothed comb to detangle if necessary. Next rinse out your first application for longer than normal at least 3 times longer, otherwise you won't remove all the silicone build-up left by previous products. Wet hair is quicker to detangle too. Dry as normal.
The subsequent cleanses I'd say play around with the number of pumps of Wen needed for your hair type, if your hair is short and fine you'd need far fewer pumps. I have a lot of fine straight hair which is below shoulder-length and I use about 10 pumps, however when I used shampoo and conditioner I'd need about this amount of conditioner to detangle and comb out the knots! My hair tangles just looking at it, at the hairdressers she allows an extra 20mins for my cut & blow for the combing and re-combing time! If I do say so myself my hair has never looked more shiny.
I coloured my hair last week and in the interests of experimentation I ditched the supplied after-colour conditioner and used Wen and found it worked very well and was far easier to comb and dry afterwards (and took away the chemical after-smell of the dye).
The Wen sale has finished now but there will be another in the summer.
http://www.wenhaircare.co.uk/default.aspx but the hair care plans are a good way to try the range including the styling products and intense conditioner, and it's easy to cancel after the first drop.
http://www.wenhaircare.co.uk/plan1.aspx