I think the EHC is blamed for more failures than it should be , but I have no scientific proof of this. And just to let you know a little about my background I have been an electronic tech for 35 years working mainly in the low voltage field. I spend hours a day diagnosing wiring, component and software related electrical problems.
The two things that have shut my bike down so far was an incorrectly programmed EHC (that was fixed by BDPP reprogramming the EHC) and the other problem that the EHC shutdown for was a loose sparkplug terminal cap. Plugwire came off and the EHC wont let the engine run on one cylinder. That didn't give me a good feeling when it died.

I used red locktite to hold the little screw-on plugcaps on now.
Anyway, during the diagnosis of the first problem I went through most of the wire routing in the battery area. There were several places that could have and would have caused a short in the wiring given enough time. One blatant example was two of the tail light wires running under the seat and being crushed by the seat. It hadn't failed yet , but it would have and the ehc could have been blamed for the problem. I also noted several places around the battery box with sharp edges with critical wires rubbing on them. Another spot for failure, so I put some additional insulation in these areas to prevent future failures. I also rerouted wiring around lower engine area, as it was just done in a sloppy manor from the factory. Even though it has nothing to do with the wiring, I found the fuel line rubbing on the coil housing, and it was already worn half way through in only 500 miles, again sloppy assembly.
I haven,t been under the tank yet or into the wiring in bars (scared to look) but I suspect there are places there that need attention also. The guy that designed the EHC probably had a fairly good idea on paper. The EHC may work great for an occasional short but I bet if that "short" pulses at 3-4,000 times a minute for an extended period a component in the EHC will give up.
Even though I haven't done it and hope not too, it looks like replacing the EHC with the PDM or the WP version requires a lot of rewiring of the existing harness. During this rewiring process I suspect a lot of problems that were blamed on the EHC alone were really wiring problems somewhere else that were eliminated during the retrofit with the new wiring. And all the crimp connectors....fine when new but after corrosion and vibration has set in there is a potential for a problem. They should be soldered. All this being said, the EHC still could be crap. Without having one to dissect, and hard to do the way they are made, we may never know if they are the cause of the problem, or fail as a result of another problem.
Sorry for the long post, just some of my thoughts.