Design and Display
The Blu Tango looks and feel cheap, not only is it light in the hand, but there are some possible manufacturing defects on the Tango. For instance, there's a small bump at the top, which when felt can easily be identified. It doesn't add to the design and is most likely an error with the manufacturing. The back cover also comes off extremely easily, requiring very little effort to pop off the back.
The Blu Tango features a tiny 2.8 inch display, which is comparable to the screen on the Motorola Charm or Samsung Replenish. One thing to note, however, is that those aforementioned phones have a physical QWERTY keyboard, while the Blu Tango does not. This means the 2.8 inch display is very frustrating to use, especially the virtual keyboard. If you have larger hands, you begin covering a large amount of the display as you type.
Also, the display itself is not capacitive but rather resistive. Many people have forgotten the days of resistive screens, when you had to apply more pressure on the screen for it to react. This is, unsurprisingly, frustrating for users who have gotten used to capacitive touchscreens. You have to wonder if the display can continue to support the pressure that it will constantly be under, as the entire phone feels cheap.