I also use this on my shelties I love it!!!! Not that exspensive either. You can a gallon and deluit it or by it already deluited. I like the shampoos as well. I use black on black on my guys and they look amazing.
I also agree with not cutting them. I work at a vet/grooming shop and I won't even have the groomer there do my dogs lol. They go to the breeder who grooms them basically a wash brushout she trims the ears and the feet that is it.
Most groomers in grooming shops are taught "pet" grooming where alot of people just want the least amount of hair as possible. Alot of the shelties we see the owners want the feathering and everything trimmed short.