Although the camera isn't something you'd want to take celebrity portraits with, photo quality was decent. In photos with dim lighting, there is a notable amount of digital noise. I also thought objects could stand to be sharper and more defined. However, in general, colors were accurate, and objects were easy to make out and in focus. You will need to keep the camera still a few moments after pressing the shutter to prevent motion blur, but I found I didn't have to wait as long as I did with previous ZTE devices.'
Recording quality was also adequate. Objects remained in focus, and colors appeared true to life. However, in quiet recordings, I could hear a low humming noise in the background. It wasn't overly distracting, but noticeable nonetheless. In noisier videos (such as cars driving by the road), this sound was not picked up.
I tested the dual-band (800/1900) ZTE Imperial and call quality was good. Voices sounded a bit muffled and call volume could've been slightly louder, but in general, voices were easy to understand and came in clear enough. In addition, none of my calls dropped, audio didn't clip in and out, and I didn't hear any extraneous buzzing or noises. Likewise, I was told that I could be heard perfectly fine as well, and when I stepped outside nearby whizzing cars, my colleague told me that he could not tell that I was outside.
My main issue, however, was the low volume for the speaker. Even when volume was turned all the way up, I had to hold the handset close to my ear, even when I was indoors, to hear my call. When I stepped outside, it was very difficult to hear my call over the general backdrop of noises.
ZTE Imperial (U.S. Cellular) call quality sample
Because we don't have U.S. Cellular's 4G LTE coverage here, I browsed the Internet using the carrier's 3G network (EV-DO Rev. A). On average, data speeds were slow but consistent: the handset loaded CNET's mobile site in 32 seconds and our desktop site in a minute and 25 seconds. The New York Times' mobile site took about 25 seconds, while its desktop version took a minute and 25 seconds. ESPN's mobile site took 29 seconds, and its full site loaded in a minute and 5 seconds. Ookla's Speedtest app showed me an average of 0.25Mbps down and 0.46Mbps up. It took an average of 23 minutes and 21 seconds to download the 32.41MB game Temple Run 2.
|ZTE Imperial||Performance testing|
|Average 3G download speed||0.25Mpbs|
|Average 3G upload speed||0.46Mbps|
|App download (Temple Run 2)||32.41MB in 23 minutes, 21 seconds|
|CNET mobile site load||32 seconds|
|CNET desktop site load||1 minute and 25 seconds|
|Restart time||45.22 seconds|
|Camera boot time||2.11 seconds|
The handset is powered by a 1.2GHz dual-core CPU. Basic tasks like unlocking the screen, launching the keyboard, and opening the camera app showed a little lag, but it wasn't overly frustrating. While it's not blazingly fast, all in all, my general experience with the device felt smooth -- no apps or games quit unexpectedly, it didn't take too long to transition back to the home screen, and the handset never stalled. On average, it took almost 45 seconds for the phone to restart entirely and 2.11 seconds for the camera to fully launch.
During our battery drain test, the Imperial's 2,500mAh battery clocked in an impressive 19.52 hours of talk-time. Anecdotally, it can survive a workday without a charge under mild usage, and last several days on standby. It has a reported talk time of 12 hours. According to FCC radiation standards, it has a digital SAR rating of 1.30W/kg.
As one of the two cheapest lower-tiered 4G LTE devices that U.S. Cellular has to offer (the other being the ), the ZTE Imperial is the better handset. Compared to the latter, the Imperial runs a newer version of Android, has better call quality, and takes better photos.
However, if you don't already subscribe to U.S. Cellular and are thinking of switching to the carrier, it's currently offering the 4G LTE Samsung Galaxy S3 for free. Even though it's been out for over a year, the S3 sports superior flagship specs like a 4.8-inch AMOLED display, an 8-megapixel camera, and a dual-core processor. This promotion may change at a later date, however, so new customers should research all their options.