If you were to compare them to cars, the BlueAnt S4 would be a Lincoln Town Car, and the BlueAnt S3 would be a Ford Focus. That doesn't mean the S3 isn't a good speakerphone, but it's just not as fancy as its big brother. It lacks a lot of the S4's higher-end features, it's smaller in size, but it is cheaper and easier to use.
If you squeezed the BlueAnt S4 down to a rounder shape, you would end up with the BlueAnt S3. The S3 measures 4.17 inches long by 2.71 inches wide by 0.78 inch thick, which is just a smidge shorter than the S4, but is a touch wider and thicker. Though it doesn't differ much in size, it's definitely not as sleek in appearance. While the S4 is clad in glossy black and brushed metal, the S3 has a simple all-black plastic shell instead. With its rounded sides and matte surface, it's a much more modest gadget in appearance.
On the front of the device is a large speaker where the BlueAnt logo sits. Directly above that is the front panel that houses all the controls. They consist of the multifunction button and the volume controls. If the buttons don't feel like you're pressing them, it's because they are all touch-sensitive. Simply tap the multifunction button to perform a variety of tasks like answering calls or pairing another phone. For the volume controls, you have to slide your finger across to adjust the volume. When the speakerphone is attached to the visor, these controls should face toward you. Next to the volume minus sign is an LED indicator.
We adjusted well to the touch controls, but we can see how some people might prefer to have physical buttons, especially when you're driving.
The S3 comes with two visor clips, each of which slides on to the back. One of the clips is for narrow sun visors, while the other is meant for slightly thicker ones. On one side of the speakerphone is a simple sliding power switch plus a Micro-USB charging port.
The BlueAnt S3 comes with a 12-volt USB car charger, a Micro-USB cable, and a user manual.
The BlueAnt S3 does not have the same voice features as the S4, so you can't say "BlueAnt speak to me" to trigger the speakerphone. However, you can perform a few tasks with your voice. You can answer calls by saying "Answer" and ignore them by saying "Ignore." To engage the voice command functions of your phone, you need to press the multifunction button first. This won't work if your phone doesn't support voice dialing.
After the initial pairing is complete, the S3 will attempt to transfer your phone's phone book to the speakerphone so that it is able to read out the names of incoming callers. Depending on your phone, you may need to allow permission for phone book transfer. You can also manually transfer the phone book via Bluetooth. If you make any changes to your contacts list after you've already transferred them, you can simply update the contacts by pressing the two volume keys simultaneously for around 3 seconds.
Aside from that, the BlueAnt S3 has A2DP streaming for listening to music or turn-by-turn directions from a running GPS application. It also has multipoint support, which allows you to connect to two devices simultaneously. When connected to two phones, the S3 can receive calls from either phone but can only stream A2DP from one.
The BlueAnt S3 does not have access to external services like the S4, nor is it compatible with BlueAnt's Android app that'll read out incoming text messages and e-mails. It does, however, have a vibration sensor that automatically reconnects to your phone when the car door closes.
We tested the BlueAnt S3 with the Apple iPhone 4. The device automatically goes into pairing mode when you first switch it on, so we paired the two quite easily. It immediately went into phone book transfer mode, and seemed to do so without any problems.
Call quality was quite admirable. Callers had no trouble hearing us over the din of the engine, and they said that our voice sounded natural as well. On our end, though the speakers do emit rather tinny sound, it worked fine for most phone calls. For A2DP music streaming though, it doesn't quite offer the bass and rich tones that we've come to expect from a good car stereo. However, it does work in a pinch if you don't have a way to hook up the phone to your car.
If you're looking to save some money and all you want is a solid Bluetooth speakerphone without too many frills, the BlueAnt S3 fits the bill. It's around $79.99 retail, but you can easily find it for cheaper if you shop online. However, the BlueAnt S4 only costs around $20 more, and you get a lot more features out of it. We would encourage you to get the S4 instead if you can afford it.