WE have stayed in both the tower and the garden wing at the CR. The garden wing rooms are identical to those in the tower, but they do not have balconies on the second or third floors. They do have sliding patio doors that open to a rail. The ground floor has patios, although they are not completely private. Garden wing views (garden view) tend to be very nice, with views over the lake, pool area, grounds etc. There are a few standard view rooms that overlook the parking lot but if you don't want that, it is fine. These are a separate booking category (standard view). Personally, we think that these rooms are often the best value for staying on the monorail. they are huge, very spacious and comfortable. They are separate from the tower but have a short covered walkway connecting to the main tower. Anywhere else on WDW property these room and views would probably be considered 'preferred'. Here they are the value option! They are convenient and not far from anything.
The tower rooms are more expensive but they have balconies and stunning panoramic views. Bay Lake is serene and peaceful, the TPV overlooks the parking lot below but also looks over 7 seas lagoon, the GF, the Poly and the MK. Views of the fireworks from these rooms are spectacular, IMO. We do not even notice the parking lot, although some people find it intrusive. It may be because we have always stayed on the 11th or 12th floors. Again, we have never had a problem with noise, but that might be a result of staying on high floors as well. The tower rooms are great, IMO, but pricey. Lower floors may be noisy? I have read this but never experienced it.
Compared to the Epcot area resorts where rooms can also sleep 5, you have much more space as the room is noticeable larger. Some rooms in the BC/YC do not have the daybed, so a roll away bed has to be brought into the room. Families with 5 have preference for getting rooms with daybeds, but they aren't always available. When you get a room without a daybed, they are smaller again. It makes for a tight fit, IMO. I haven't stayed in a BWI room without a daybed, so I am not sure if they all have daybeds or if I have just been very fortunate. In any event, if I had a group of 5 wanting to say in one room, I would want at least the size of a MK resort.
As others have said, it will be when the discounts are released that you will know for sure which option will be the least expensive. Meanwhile, I would book a room that I would be happy with without a discount and book simply change the reservation if something better comes along later.
Good Luck!