As Shruti often remarks, I (almost) only travel abroad for mathematical visits.
My visits to the USA are usually of at least a month's duration and I do have an official address during his period. I have a lot of family and friends in the USA whom I like to call when I visit the USA. Of course, I want to call India as well! Finally, it would be useful to have some data connectivity as well.
The above parameters set out the requirements that I have for phone facilities when I am in the USA.
This year, as Shruti was enjoying good connectivity with Uniconnect during her trip to Germany, I followed suit and bought a Uniconnect UNI65 connection at Delhi airport in the Departure area. I think that this was mostly a mistake, and I think I have a better solution as explained below.
The Uniconnect deal was a thousand rupees for the activation and SIM card followed by three recharges of 500 rupees each. Each recharge gave me UK Pound 5 worth of minutes according to a predefined charge rate. In my muddled way, I thought the charge rates sounded reasonable (which they are when compared with roaming charges) but they are 10 times what one can get from the different solution outlined below.
It is also worth pointing out that most cell companies in the USA charge for incoming calls (and Uniconnect does too!). When one calls out using UNI65, the receiver sees a strange number which is from the Isle of Man and not the USA number you have given them. This means that your calls are often not answered until you have explained this anomaly to them!
There is no data support with UNI65. This left me hunting for a data connection during my first week here.
All in all, I spent an equivalent of USD 42 for a connection that lasted me less than a month in the USA and (more importantly) severely limited my connectivity during this period. (By the way, the Matrix deal sounded, if anything, worse!)
To be fair, I should emphasise that I had almost no connectivity issues with Uniconnect and I did manage to use it for a number of important calls! It just does not fit my needs.
My current solution has been to buy a T-Mobile SIM (1 cent online!) along with a per month USD 40 "prepaid" plan which has unlimited calls and text within the USA and 400MB of bandwidth. The latter is enough since one has Wi-Fi at home and in the office, so one only needs this bandwidth on the road. (You can also pay USD 50 to get unlimited bandwidth with a throttle after 400MB.) There are alternatives for longer periods as well.
Skype or some other IP telephony solution for international calls is convenient only when one is making calls at pre-determined times; it is not for casual calls. So needs a "proper" way of calling someone who may not be hooked into the internet at the time when one is calling.
To call India (or outside USA), one can use Reliance India Call which is a few cents per minute! A USD 10 charge will give me more International call minutes than I have used so far! There is an app for Android that makes it convenient to use Reliance India Call.
Bottom line, if your use case is similar to mine, avoid UNI65 from Uniconnect. Instead, investigate a local SIM which suits your needs and add an international call service; in my case, T-Mobile and Reliance fit the bill. This may cost a bit more than Uniconnect but will leave you more carefree about your phone usage.