i disagree. always better to be prepared & not need it than to be caught w/out a good step-up on a trip. personally, i think i'd go for the gravy along w/ the step up. gravy's a good, performance based all around shape that should be good up to a couple feet OH. step up from there. flyer doesn't have much more (if any) capability at the upper end of it's range, but the gravy will work well in smaller surf better.
bring whichever you have spent more time on. going away on a trip I always want to feel comfortable on my board...experience on a board can sometimes allow you to push the prescribed size limits that the shaper claims. Plus you're only gonna be gone for a little while so you don't want to waste time adjusting to a board you haven't ridden much. have fun.
U picked a great spot though. Playa Negra is my favorite spot on the pacific coast - the water is crystal clear and the wave is super fun. It's predominantly a right but there's a break down to the left that u can surf either way.
I went a few years ago and stayed af the hotel right on the break. The prices werereasonable and the food was good. Most importantly though the surf pumped for 10 days. I would probably bring reef booties to surf at low tide when it's shallow. That's when u get the best barrels but there r urchins all over the place.
It was solid eight feet when I was there on the best days and the locals were only riding shortboards but they definitely have the place wired. Apparently it just gets better as the surf gets bigger.
I'd go with the most versatile board and definately bring two boards. the local boards are cheap and fragile. I brought just my fish when I was at Playa Hermosa but wish I had another board for Bocca Baranca. sometimes at Hermosa I needed a smaller board than the fish as well. Bring more than two leashes. I snapped one and had to use my big wave leash at Baranca. Too heavy a lease for that place. Of course you get to surf Negra. Very different. Pura Vida!