Visited Isla Ometepe on March 2008. I did some homework before where to stay on island and from Villa Paraiso and Charco Verde I chose Charco and I'm happy I did that.
I did my reservation via e-mail.
Place is 5-10minutes drive from harbour. There was no problem with taxi.
CV is situated on the shore of Lake Ometepe and it''s quite a nice. They have restaurant there and some rooms on the shore and some cottages some metres away.
We had cottage and I loved it. There were nothing unnecessary but all I needed I got - AC, hot shower and plenty of room.
The food in restaurant was good ((I'm not very picking person) and especially good were fresh juices.
Every evening after the bar was closed we bought some local rum (Flor de Cana) and sat there till the late night. Barmen were very nice. They didn't know english very well but we always could understand each other.
Some price examples - Victoria beer C$20, Nica Libre C$25 (my favourite), Jugo Natural fresh juice) C$15 (please, try it).
One of the employees also organised for us minivan who took us whole day around the island.

So if You love nature and don't need servants on every step I suggest to choose CV.