- User Interface: The Samsung Vibrant is running Samsung's TouchWiz 3.0 user interface while the G2 is running a stock version of the Google Experience. TouchWiz differs from stock Android in a number of ways, including the homescreen widgets available, appearance and some Android enhancements characteristic of TouchWiz. Overall, however, the core functionality of Android remains the same on both devices, and the choice between the two interfaces is one of personal preference.
- Operating system: Although the Vibrant is expected to be upgradeable to Android 2.2 Froyo in the next number of months, the T-Mobile G2 is already running Android 2.2. With Android 2.2, the G2 offers support for Adobe Flash 10.1 along with mobile hotspot abilities and a potentially speedier user experience.
- Power: The Vibrant is equipped with an ultra-fast fast 1 GHz Hummingbird processor and 512MB of RAM. Although still a very snappy device, the G2 by HTC has only an 800 MHz processor, but has an equivalent 512MB of RAM. In day-to-day activities such as web browsing or checking email, the difference in power between the two devices won't be significantly noticeable, but may make a difference for power users.
- Display: The Samsung Vibrant has a large and gorgeous 4-inch display with 480 x 800 pixels. Because of its large display, the Vibrant is an ideal mobile device for movie-watching and web browsing. The T-Mobile G2 has a slightly smaller but still sizable 3.7-inch display. The Captivate is equipped with an ultra-thin Super AMOLED (active-matrix organic light-emitting diode) screen. The AMOLED screen will provide a number of advantages, including a brighter screen, less sunlight reflection, and reduced power consumption.
- HSPA +: The T-Mobile G2 offers connectivity to T-Mobile's next generation HSPA+ network, allowing the device to reach super-fast download speeds approaching or exceeding 4G speeds (3 – 6 mbps average). The Samsung Vibrant is limited to standard 3G connectivity.
- Camera: Both devices are equipped with an advanced 5-megapixel camera with autofocus. The T-Mobile G2, however, touts an LED flash for improved photos in low lighting. The Vibrant is capable of capturing HD-quality video at 720P. Whether the G2 will be capable of capturing HD video remains to be seen.
- Storage: Right out of the box, the Samsung Vibrant offers 16GB of on-board storage space and also will support up to a 32GB microSD card, making for a possible total of 48 gigabytes of storage. While unconfirmed as of this comparison, the T-Mobile G2 by HTC will likely have 4GB of on-board storage space, as well as a pre-installed 8GB microSD card. Accordingly, the Vibrant offers 4GB more storage space right out the box than the G2, although a larger microSD card can of course be purchased to replace the 8GB card.
- Samsung All Share: Featuring DLNA (Digital Living Network Alliance) technology, the Vibrant is able to wirelessly send user-generated video content to other DLNA-enabled devices, such as TV's, monitors and laptops.