Hello,
We just got back Sunday from 3 days on the Wonder. We stayed in room 7505 and we didn't know the family that stayed in 7507 at all. I was very concerned about the noise issue because I had read that the connecting rooms allowed for more "next-door neighbor" noise. Either the family next door were usually as quiet as church-mice or it just wasn't a problem. I did hear the little ones next door occasionally but never enough to disturb me or anyone else in my family.
We found the forward location to be very convenient for the shows since the forward elevators open up just outside the Walt Disney Theater. The location of the room was close enough to the forward elevator to be convenient but far enough away to keep out all the elevator traffic noise. The only downside to the location was that it was on the opposite end of the "secret" deck on 7 and the laundry/ironing room was on the aft end as well. We didn't find it to be a big deal, though.
Not having a window did not bother us at all;we were usually only in the room to get ready or to rest. It was, however, VERY difficult to wake up in the morning without natural light so make sure to get those Mickey wake-up calls each day!
I personally love, love, love the split bathroom floorplans in the Cat 10 and above. It is extremely convenient when having multiple persons get ready and also gives needed privacy. We were really looking to save money this trip but decided that the extra money for the split bathroom would be well spent and we still feel that same way.
I hope you have a great time whatever you decide. If you have any more specific questions, just ask.
King'sLady