The rest of the hardware in the Alcatel One Touch 991D is not very impressive, but that is to be expected for a phone in this price segment. The 320x480 display is clearly a TN panel, which means that the viewing angles aren't great. Particularly from above you can't see very much. The brightness of 250 candela per square meter is not very high. Touch operation works really well, however, and the virtual keyboard also works great.
Alcatel used an SoC that we don't see every day, the MediaTek MT6573. It's a somewhat older chip that utilises ARMv6 architecture and a single ARM11 core that runs at 800 MHz. The phone has 256 MB of RAM. The internal storage space of 512 MB is pretty limited, but you can expand that up to 32 GB with a micro SD card. However, there are a number of applications that won't go on a micro SD card, and then your 512 MB will be maxed out pretty quick. Without adding anything yourself, the available internal space is already limited to 100 MB.
The dual-SIM feature won't be useful for everyone. In areas where not every provider has good coverage, it can be handy to have to SIM cards in the phone. Another interesting application is that you can separate your professional and your private use this way, or if you want two different numbers for other reasons. There is one limitation, and that is that only one of the SIM cards can take advantage of 3G, the other SIM card only goes to 2G.
The 991D has two cameras. The front-facing one has a resolution of 0.3 megapixels, and the main camera has 3 megapixels and LED flash. The quality is acceptable for this type of phone, social networks are full of photos taken by these types of cameras.