Bloom,
I have stayed at the Hemingway several times over the past few years. It is indeed close to the action. It is located directly beside the Hotel Castillo. As for being chica friendly.....I would say it is more "chica tolerant." When I stayed there, they charged a $10 chica fee. Keep in mind, the Hemingway is very much the type of hotel that attracts the "eco-tourists," and it is quite possible that should you bring a chica back to the hotel........ you will take the "walk of shame" in front of the other guests.
The price wasn't too bad, and the breakfast is "adequate." The rooms are antiquated.
If you need more info, let me know.
Zebra