Gran Destino Tower rooms vs regular CSR rooms are in some ways sort of apples and oranges in my book. GDT is arguably a deluxe masquerading in a moderate resort. The rooms are new, spacious, clean and very warm (in my opinion). I find the overall GDT building breathtakingly beautiful and having everything you need under one roof is very convenient. The backstory of the Walt / Salvador Dali connection and how it's woven into the the building and architecture is actually quite interesting, especially if you're a Walt fan. People give Disney grief for all the IP infusion at other places, but GDT is like a brand new example of the exact opposite. If the rooms had balconies I would consider it pretty close to perfect (the fact they opted not to do balconies does make it feel a little generic, perhaps - I do think they cheap'd out on that part). I guess maybe 'generic' = a good conference hotel/resort that may have broader appeal, but to me it works.
Obviously with the regular rooms you have external hallways and some can be further from the main building/amenities, if that's important to you. I like them too, it's just a different setup (and I prefer indoor hallways).