Hi Emma
I have never used doggy day care but I can't imagine that it would be a very good idea for a puppy- especially a Velcro cocker!
I believe it is extremely important to develop a really strong bond of protection and security for your little pup who will be away from its mum and litter mates and in a strange new place. It needs plenty of time to settle in and to know who it's new family is, and all its new experiences (and all the socialization trips you have to do especially In the first 16 weeks) need to take place against a background of consistency and comforting routine.
I would imagine that doggy day care while it is still young could be a bit confusing for it and depending on its character, possibly upsetting (mine has a little whimper every time I go upstairs to the bathroom!). I'm sure doggy day care for some dogs can probably be fun for them but I don't know about a young Velcro cocker puppy.
Just as a comparison, when we got our pup, I had 2 weeks off work and cancelled all my appointments. I only work part time anyway, and there is only a 2 hr gap between me going out and my husband coming in. I devoted the first 8weeks of having the pup to heavy socialising, taking her everywhere with me so she could see every different type of environment possible- town, traffic, etc and be handled by as many different types of people as poss. Even with all this, when she was 6 months I realised she was scared of cars(we are rural so don't see many) so I have recently been re-doing traffic watching and pavement walking, which she is much better with now.
Our pup is fantastic with people of all kinds and dogs of all kinds but not without a massive effort on our part to make sure she was exposed to lots of new people, dogs and places daily. It is hard work but time put in now should make a fairly bombproof dog for the rest of her life.
I personally wouldn't want someone else to be looking after my pup at such an important formative stage in her life. Even though they drive you mad, it is nice to know exactly what has happened to your dog so far. This is just my opinion. I don't speak tor anyone else and I am not criticising doggy day care, just it's suitability for a very young cocker.
I'm sure someone will be along soon with the other side of the coin, which will help you to see both sides of the issue!
Best of luck with your little furry friend.