Where are you staying when you go back in eight months?? (I see the timeline on your signature)
We spent our 10 year anniversary at POR and really loved it. We've stayed there two times since then as well. I wouldn't think GF is $1,000 more romantic than POR as far as the grounds, etc. But, do you guys like to order room service? Sit out on your balcony? Relax while wearing robes? (I'm assuming they provide robes, maybe not, though). If you say yes to all of those things, then maybe GF is where you should be. Another consideration is being able to land a confirmed reservation for a King room at POR, many of their rooms are double/double. How do you feel about possibly being in a double room vs. a king?
Finally, the weather is going to be hot during your trip. How do you feel about waiting for the buses? You're only there for four days so maybe you want to speed things along by being on the monorail.
Like I said, we love POR and find it to be very romantic but if you want some key items for this special trip, then I'm thinking the GF is where you need to be!!