Just got back from DL and we stayed at the Residence Inn and had the same type of room. I am a Marriott Rewards member and stay at the Residence all the time. It is a wonderful hotel no matter what city you are in. During the week, they serve dinner for free and also every morning they have bagels, donuts, cereal and all kinds of breakfast stuff.
The penthouse has an upstairs so if climbing stairs does not appeal to you, ask for the 2 bedroom suite w/ hot tub. It is all on one floor but costs a little more. The hot tub is on a little private patio... very nice. Some of the Residence Inn's do not have this room but it does not hurt to ask.
The room you are staying in is usually called the Penthouse Exception. Ask them if they have one better and how much more does it cost. Sometimes they are the same price.
Be Aware!!! Marriotts are horrible about giving your room away to Rewards Club members who show up unannounced or decide to stay longer. If this happens, make sure you throw a fit in the lobby and they will take care of you. Like I said, I am a member but I've seen people show up probably a dozen times only to find out they do not have a room or do not have the room they reserved. The ones that complain either get upgraded for no more money or are given a smaller room at no charge. I've even seen them send people to another hotel and pay the bill for them along with a gift certificate at a nearby restaurant. Just wanted to warn you.