well, almost all groomers have their own version of a cocker cut. Some shave everything off - EVEN THE EARS OMG, I call that the Beagle Cut.
Some like to do a puppy cut, which is really nice for the average pet cocker. Some like to leave a little skirt on the sides, legs fluffier and have back shaved down (sometimes too short if you ask me),
but mostly it's how the owner wants the dog to look, depending on their lifestyle. If you don't have time to brush a few times a week, a shorter puppy cut is great. If you & your dog like the bonding a nice brushy gives, then go for a little bit of fluff.
Some like topknots, some like nekid heads. I prefer to have a cocker at LEAST have a cocker head -- longish ears, top 1/3 groomed shorter, against grain, with a topknot and tight face/neck.
Even if the dog is nekid - at least they still look like a cocker should. Your best bet is to look at Cocker Pictures (breeders pages, etc) and find one you like and print it out for the groomer.
Also find out if the groomer has done many cockers. Many don't like to do them, because they might not be used to feet being fiddled with or ears being messed with.
I'm putting all our dogs (here) in a puppy cut - no matter what breed, each one has a puppy cut, or sometimes called a "teddy bear".
Ling Ling (my black & tan) has a beautiful show coat, but I keep her in a cocker puppy cut. Heres what it looks like on her.