Gen III UPB

My current switches and units are UPB Generation I and there has always been problems with reliability. Perhaps 1-2 in 10 switch changes do not get recognized correctly by the linked unit. Some of the units have failed altogether and I need to replace.

My question is whether generation III is much better than generation I UPB?

Thanks for all the help.

I have a similar situation to you.  In my current house its all Simply Automated Gen 1, but I'm buying a new house, and there is no question I want UPB there as well.
 
You mentioned two things that you need to clarify.  You said switches have reliability problems, and you said some have failed altogether.
 
This could mean many things. First, what brand switches do you have, and how have they failed?  I have 65 Simply Automated devices, and maybe 3 or 4 have failed (over 10+ years) because the contacts in the switch wore out simply from constant use. I've never had one actually have the UPB part fail or electronics fail (other than switch contacts).
 
On poor reliability you can have a poor signal level or a high noise level. You want the highest signal and lowest noise. In my experience, signal is a bigger problem then noise, but in some cases, noise can be a problem as well.
 
Do you have a coupler between your two electrical phases? Is the switch that fails always on the "other phase" as reported by UpStart? 
 
From my research, the Gen I, GenII, Gen III stuff is misleading, because there have been many improvements through the years that are not represented in the "Generations."
 
We can talk more GenI, GenIII once we know more about what YOU have.

Thanks very much for your reply. Really appreciate it
 
I am in Australia on 50Hz 240Volt AC. All of the switches and units are from PLLC http://powerlinecontrol.com/  
 
They were fairly early models for them circa 2008 and they claim that they have improved their switches and units substantially. My plan was to gradually replace switches and units starting with the most problematic ones.
 
Yes, my greatest issue is with the phase coupler. UpStart cannot find it and I cannot read or write to it. The lights flash on the phase coupler when there is any activity but it seems that signals are not crossing between phases. Switches can only control units t hat are on the same phase.
 
I will start by replacing the phase coupler and then try reprogramming the switches and units with problems.    

There are TWO types of copulers; a phase coupler is a passive device and usually has no flashing lights, and phase repeater which is an active device. Phase couplers work with all UPB devices, but they only work fair. Phase repeaters are $250+ and work great but only with more recent switches. If you have a repeater, and try to use them with older switches that don't support them the symptom will be that UpStart can't "see" the switch. A repeater can make the situation worse if your switches don't support them.  A phase coupler is required instead. At least that is how it works in the U.S. with two 120V phases that add to 240V.
 
You say you have 50hz 240V, but do you have 240v at all outlets and are your lights 240V or two phase of 120V that add to 240V? 

I have a 3 phase repeater and it was working fine with my switches and dimmers for a first 4 years or so. Now, wherever I plug the PIM into UpStart can only find the units on that phase and not the other two.
 
In Australia we have 3 phases of AC power and each is 240Volt. All circuits in the house are connected to one of these 3 phases and all lights and outlets are 240 Volt.   

Sounds like the repeater is no longer working.

Have ordered a replacement and hope to install next weekend.