What kind of real world wireless range are we talking with Agilent compared to the Fluke system? The Fieldpiece meters are spec'ed at 75-100 ft without the use of repeaters. Not super accurate, no realtime graphing and looks battery hungry but they go quite a distance over the others. Here is a demo of one of the Fieldpiece meters
Agilent currently uses Class 2 Bluetooth, so around 30 feet. Fluke is using Zigbee, but at 2.4 GHz, so they're not going to be seeing any better signal penetration in concrete buildings than what Agilent has and their range will be similar. I don't know what protocol Fieldpiece is using, so I don't know how useful that 100 ft range they advertise is, but I do know that Fieldpiece is a very rare brand among electricians and technicians outside of the HVAC domain here in the US and their products aren't very well known. Fluke, Agilent, Hioki, AEMC, Megger, Ideal and Klein all advertise regularly in trade mags for the electrical industry - Fieldpiece, never.
The main difference between the Agilent and Fluke systems is that Fluke has created a supposedly "user friendly" system but one which isn't very upgradeable by users or very elastic in use or that offers any kind of backwards compatibilities - in general it assumes it's users are just plug and play capable. Agilent's system allows you to make use of your existing gear - some of which already has datalogging built in, it offers regular software updates, offers much more flexibility with what you can connect and monitor, works with your phone or tablet or PC and allows users much greater ability to customize what they do. All in all, I can't imagine wanting to switch systems - it would be a huge step backwards.