The real deal between a studio at a DVC and a moderate room is that at a DVC resort, you are in a more luxurious resort! You will have a much better location and many more amenities. Plus, you have a small kitchen to use (microwave, fridge, coffee pot, etc. that are very nice).
The sofa beds are comfortable, but not as comfortable as a real bed. No denying that. It hasn’t ever been an issue for us.
As for the housekeeping, it is not much of a bother! Our family usually prefers no housekeeping even at a regular hotel, anyway. If I remember correctly, you will get housekeeping services on the 4th day, and you can also arrange for towel service whenever you like. You can also arrange for a housekeeping visit any time you like. You will pay a small fee, but it is easy to arrange teh extras.
We love mods, especially POR. But you can definitely tell a difference in the level of amenities and service at a DVC resort, and we feel it is absolutely worth it.
For instance, you can arrange for groceries to be delivered to your room on check-in day at DVC too! Lovely. One of our favorite parts.