There is likely a lot more to this equation. Pings are low priority and subject being dropped before other traffic. How high up are the APs mounted, and how are they mounted? Are you stationary when you test or do you roam? Have you performed a wireless site survey to ensure the channel/power settings are good? Have you tested with a more fully functioning device (ie. a laptop)? Have you spoke to Honeywell about their best practices?
The last point is very important. A number of handle scanners have been problematic until the vendor of the scanner was engaged to suggest the best settings for the devices. For example, roaming aggressiveness has been a main culprit in poor performance.