I may have made a mistake...

I went ahead and booked Hard Rock (oddly enough, there was nothing left but Club Level at Royal Pacific!) for next May. I picked from the big three because I wanted those Express passes. Now by doing the math I see that if I did Sapphire Falls and paid out of pocket for Unlimited Express passes, that would actually be a couple hundred dollars cheaper. Any thoughts? Are there other benefits that make it worthwhile to stick with Hard Rock? I like the theming of Sapphire, but I know it's a bit further form the parks...

We took a walk around Sapphire falls in Feb. And it looked like a really nice resort. The main thing you'll be missing is being walking distance to the parks. In our experience when we stay at Cabana Bay we missed walking to the parks more than we missed having express pass. For us the huge savings we get with military discount at Cabana Bay makes it worth it. The main perk we miss tho is walking to the parks.

May 2018?
I would definitely keep looking. Every time I've booked Universal, I would check periodically. The prices went up and down and so did availability. My only caution is that if you see a deal, book it then because it may not be available the next time you check. For our trip last February, one time I was just browsing and they had a deal on club level Hard Rock that ended up being cheaper than the regular room rate I paid. They are also good about moving your reservation or giving you credit if you find a better deal.

We like express pass and walking to and from the hotel. As I posted before, my family liked Hard Rock more than Royal Pacific because the walk to and from is the easier and for the pool. We never considered Portofino because you are more dependent on transportation.