"Worth it" is very difficult to determine with hotels & DL.
...Are you willing to pay $1500 for: extra magic hours every day (this perk is MUCH more useful at DL than it is at WDW! We love it!!), closer location, ability to charge to your room, package delivery, & better hotel theming? Because that's what you'll get. Or for 1500 more do you expect a wonderful hotel room and maybe some free food and first class service? Because you WON'T get that from DLR hotels and might spend the whole time feeling like you're being ripped off.
First off, don't forget that the GCH is currently undergoing a major refurb of the pool areas and the rooms (a few at a time), the Lobby gets a major remodel this summer.
But it seems like Disney is doing you a favor, more expensive,won't even offer a reserved type of bed ("Request" only, no guarantee). The off-property Full Service Hotels have much nicer and faster check in, 24 hour room service, etc.
Staying off-property can save you money too, as stated, most offer a free Hot Breakfast, options to eat nearby at lower prices than the Disney options, places like CVS and Walgreens to get some basic groceries you can take to your room (most have a small fridge and microwave) and souvenirs.
Also, Hotels/Motels that are the same basic distance as the Paradise Pier to the Main Entrance Plaza offer some sort of shuttle if you are tired of walking, instead of the 3/4 mile walk from the PPH each way, with no other option offered. (places like HoJo's and the Courtyard, Candy Cane Inn and the Hotels at the corner of Harbor and Katella. Also, the chance to earn Frequent Stay points with the major chains.
To me, in Anaheim, the "Disney Bubble" isn't worth the amount the charge as compared to the other nearby choices.
In Florida, IMHO, for most folks, it pays to stay on Property, but then Disney has a lot more price options in its Hotel offerings, due to the size of the place, and many more Hotel rooms in their inventory.
But everyone travels differently, and I can do a lot with an extra $1,500, extend my stay/vacation, visit other attractions like Knott's Berry Farm (about $50 per person for a day), a nice dinner out, or a Dinner Theater show like Medieval times and Pirate's Dinner Adventure. Heck, even better seating on the flight to/from Anaheim, that is usually worth it to me. (The low cost upgrades, such as early seating on Southwest, not the First Class fare option).