If you think one hotel will pale in comparison to the other, the order may not matter. Are you committed to your reservation?

Personally, having been to both more than once, I'd add nights to Nayara. So much to do in the area and much closer to get to them. And Nayara is SO pretty and feels so much more 'Boutigue' because it is. You don't say if you're traveling with kids, but if not, unless you're staying in the Adults only section, it doesn't feel very relaxing or laid back. As for which to do first, I like being closer to the airport for departure, but that's just me.

Allyam shares an important point. Flight times may necessitate being closer to the airport your last night. Similarly, you may arrive late in the day, and getting to Nayara in the dark is not ideal. Even if you're being driven, it's a shame to miss the views along the way and not see the property well until the next morning.

In my opinion, you need at least three nights near Arenal; four is not too many. If you prefer smaller boutique hotels, I would think you could find one on the coast for the other few nights.

Thanks all! I decided to fly in from Liberia and stay at Westin for 3 nights first before switching to Nayara Gardens for 4 nights. We are bring our 12 year old with us!