I loved the Lazy Parrot. Stayed here for 5 nights during a recent surf trip.
It is difficult to find but so is everything in Rincon as there's often no proper signage. The inn is located in the hills, about a 5mins drive (max) from the beach. Rooms are spacious and clean. Staff is friendly and helpful, I was e.g. looking for a good massage place and they looked up several places for me until I found one that had availability. One comment: the reception is only open until 5pm (I think), so if you arrive late let them know in advance.
The inn has two restaurants, the Rum Shack, which is a poolside bar and serves pretty good food (even though only from a small menu) and the LRP. I ate at the Rum Shack a couple of times, the LRP was closed for a few days. There's a small store and bakery right by the hotel as well as Banana Dang, which serves terrific coffee drinks and smoothies.
I don't see the issue with the many stairs, it is really not as bad as people make it seem and if anything, it is a good small workout. I also don't agree with the supposed americanization of Rincon - yes, you here little Spanish, but that applies to all of Puerto Rico and there are much fewer American chains here than in most other locations on the island. Rincon is a typical laid-back surfertown which simply may or may not be your cup of tea. If you expect fancy resorts and the like, this is not your place. Also, I am over 30 and didn't find the crowd at the LPI or Rincon generally too young.
If I come back to Rincon at some point, I would stay at the Lazy Parrot again.