A forward scattering approach, for gain-bandwidth limitations, is tested on real user devices. This theory gives tight bounds on gain and bandwidth for electrically small canonical antennas of any shape. Here, the practical usefulness of this theory is investigated for a number of antennas on user devices of various sizes and operating frequency bands. Inputs to the analysis are: measured or simulated full-sphere realized-gain patterns, and estimated dimensions of the devices. The output of the study is the fraction of the obtained gain-bandwidth product and the maximum possible gain-bandwidth product for a given form factor fitted to the user device.