Disney intra-resorts transfer is easy and relatively painless...but if the rules and procedures haven't changed since January of 2007 (the last time we did it), there are a few things you need to know to keep it from being frustrating:
First, you can't just leave your luggage in your room and leave...you have to be there when Bell Services comes to pick it up. This is not a hassle at all, but IS something you need to know! They're pretty accurate and very reliable...if they say they'll be there in 20 minutes, it'll certainly be within 5 minutes either way of that...if you specify a particular time (e.g., call the night before and ask for them to come get your luggage at a particular time the next morning), they'll be there within a minute or two of the time you request...
Next, ALL intra resort luggage transfers are done between 1 and 3 in the afternoon (at least that was the process in Jan, 2007...I won't swear it hasn't changed!)...so you will not be able to get your luggage back (whether or not you can get your room in the new resort earlier than that) until after 3.
Finally, you must be in your room to receive your luggage. Again, you can call when you get back to your room and they'll tell you how long it will take and it'll be generally accurate. Or you can ask for a particular time. But they will not just drop the bags off.
Each bell services person you deal with (pick up and drop off, both resorts) will "expect" a tip. I never didn't give a bell hop a tip, so don't know how nice they'd be (or not be) if you didn't tip them. But clearly they each did expect a tip!
This is the process whether it's a CRO resort or a
DVC resort. Our first time we did this we didn't know any of the above and experienced some frustration...not being able to get our bags before 3, and then having to be in the room to get them (very different from Magical Express)! But once we knew the rules, it was very easy, very painless, and a terrific service! It does get "pricey," tho, if you have multiple bags to transfer. At $2/bag (the going rate where we come from), for 3-4 bags, 4 times comes out to $32 or so...a cab might well turn out to be cheaper!
Good luck...