Hey Kyriacos,
From my experience as a 1st AC, working and/or testing with: analog Bartech, different flavors of Arri WCU/EMC/SMC, Heden, Hocus Axis1, Chrosziel MagNum, Chrosziel Aladin, I can tell you a few things:
The good ol' analog Bartech is my personal favorite. The lower-freq 900MHz signal punches through walls very nicely, and it doesn't need to re-establish a 2-way 'handshake' type communication after losing signal. Anytime the receiver manages to decode a single data packet, it immediately snaps to the desired position and you can keep working. It's reasonably comfortable, it's built like a brick, and it has no noticeable delay/latency. BUT it has a very significant feature missing: auto-callibration. That pretty much puts it in the museum nowadays.
All of the Arri FF's seem to use the same wireless protocol; fast reconnect, great range, very low latency, auto-cal. But the price is definitely on the high side.
Hocus Axis1: surprisingly, very low latency for such a low price, and good range. The least comfortable hand controller of all the ones i've held, and it makes an annoyingly loud SNAP when hitting the end stops of the knob.
Now, onto Chrosziel:
The MagNum, which i've worked with more frequently than I would've liked, has a very comfortable hand unit, similar to that of the WCU. Unfortunately, it also has a noticeable and extremely annoying latency, in the order of hundreds of milliseconds (less than 100 is pretty much unnoticeable). The latency is small enough that it doesn't seem to be noticed by inexperienced focus pullers, or other people, but I've seen several FP's blame it on the motor. The latency is so big, though, that any focus puller's reflex is pretty much irrelevant.
What I would wish for, for the ultimate perfect WFF, is Arri's ergonomics, combined with Bartech's wireless latency and protocol.
The Axis1 is the lesser of all the evils, IMHO.
Regards
