I spent a day using the phone and found it to be dependable and easy to use, despite that fact that its hardware and features are far from top-of-the-line among Android phones.
The phone's single-core processor was sufficient for the modest tasks I tried to perform using the phone's (Froyo) OS. LG says that the Optimus is easy to upgrade to Android 2.3 (Gingerbread).
The 3G phone uses GSM/UMTS cellular technology, so it will work with an inserted SIM card from AT&T or T-Mobile.
Optimus Black is smooth and all-black, with rounded corners and no hard lines or protruding buttons. It's 4.8 inches tall by 2.5 inches wide. It's 0.36-inch thickness slims down to 0.23 inch at the sides on its bottom, creating an illusion of even smaller size.