We stayed at Villas Gemelas for 8 days in Jan 2011. The house was perfect for our party of 5 (2 couples, 1 teen).
Villas Gemelas consists of 2 side by side 3 bedroom units. The mirror opposite units have: kitchen, dining and living rooms arranged from front to back on the shared wall. The outside walls have bedroom (2 twin beds) bath, stairs, bedroom arranged front to back. Upstairs is a landing with doors to a bedroom, bath, and rooftop patio. All of the rooms are of generous size and typical local construction and decor. Furniture is typical rustic Mexican fare: not the most comfortable, but we didn't spent much time on it. The kitchen is fully equipped with fair quality appliances and wares (a toaster and better cutlery would be nice). Glass walls with sliding doors and screens front the living room and 2 beach facing bedrooms: sunrise views are fantastic. There is satellite TV and a nice audio system in the living room (no dock, bring a phono-RCA cable set to play your ipod). There are no tv's or other electronics in the bedrooms. Each of the bedrooms has an AC unit and all rooms have ceiling fans. The home is clean and well maintained inside and out.
Other amenities: small library of paperback fiction, highchair, cooler, many beach chairs, hammock.
Absent: snorkel gear, portable beach chairs, portable shade, WiFi, toaster, hair dryer, iron, laundry
The beachfront is coarse coral sand with nice screen plantings between the 2 units and the neighbors on either side. The private beach area is ~120feet deep then ~30' public beach to the water. Each unit has it's own palapa and enough chairs for all guests (3 chaise, 4 adirondack): the private beach had both sunny and shady areas so everybody can get the exposure they desire. One single and one tandem kayak are included with rental to simplify getting out to the reef for snorkeling (no PFD's though). There are onsite staff who reside in a small house at the road who maintain the property. Service was great, they were very friendly and usually available if we needed anything, but we never felt they were "too" present.
Villas Gemelas may not be the most luxurious, extravagant or modern of accommodations available on Tankah Tres but it is an very good value and we found it perfectly suitable and comfortable for our party of five. We would recommend it to friends and family without pause.