We were in the third pod on the Zebra trail; right past the elevators. From our perspective this was a prime location. We could take the Zebra trail elevators to the Mara and down to the lobby to catch the busses. We weren't a very far walk to the main elevators to get up to the 6th floor lounge. I suppose in an ideal world, the lounge would be right on your floor but truthfully, we didn't find the schlep up there to be an issue. It certainly didn't keep us from enjoying the lounge.
Knowing you're going to be on the 4th floor, you should look at the resort map and think about where you want to be. We wanted to be on the bus side of the resort and we didn't want to be too close to the lobby b/c we wanted to be more in the middle of the savannah. However, we didn't want to be too far out. The pod we were put in was about perfect for us.
I agree you should let IPO know if you have any room requests. It also helps to check in early so that if you don't like where they're going to put you, you have some chance at getting a better location.
We really liked the lounge and club level CMs. It's not the Ritz Carlton, or even a Hyatt, but the food offerings were plentiful and the CMs were very friendly.
My one caution regards the busses. Not that AKL is any worse than any place else; Disney Transportation is what it is. But after two trips at the CR when getting to MK and Epcot was pretty easy, we found the wait on the busses to get any place a real drag. The first few days we were still Drunk on Disney and didn't care. But after a few days, it started to wear on us. In fact, for dinner most nights, we took a cab. Much faster. My recommendation is to rent a car.