The GCH suites are a bit more elegant and cozy, the DLH suites are more spacious. Just depends on the atmosphere you want and how many points you want to spend.
The DLH rooms are a little "older" feeling, with a more traditional hotel feel. We had an excellent view from our room on the park side of the Wonder Tower, and could open our sliding doors to hear the fireworks music and see them very clearly. They do have the Pixie Dust wallpaper border, but you need to leave the curtains open for it to really work well. The bathroom was a doorway in the master (King) bedroom, which has a sitting area and it's own sliding doors. (They don't really have balconies at DLH.) There was a small "kitchenette" with refridgerator, microwave, and a breakfast counter. That was definitely handy.
The GCH rooms are very "warm and woodsy", with the grreens and extensive use of wood in the decor. Our GCH suite had a nice living room with the pull out and then was separated from the master (King) bedroom by a corridor that was the bathroom. Sinks on one side of the small hallway, toilet and shower on the other. We also had 2 balconies, since we were on the corner. We could actually talk to someone coming off the GRR ride (and did, as we were locating a friend). There was no kitchenette, although they do have dorm firdges in all the rooms.
In the end, we were satisfied with both - the GCH was so comfortable and the standard we like, but we also couldn't beat the point difference for the DLH and how it met our particular needs that trip - we had the whole lock-off, as we had another family with us. It served the same function as a 2 bedroom unit at WDW.