hmmm, not quite - 5 mins at max continuous isn't going to cut the mustard in pretty much any helicopter role and a 20 minute max life????
Why haven't Extra elected to use a generator with a prop in the slipstream on it? Cooling issue perhaps with going longer than 20 minutes?
It is a small step in the right direction but a very long way from challenging a conventional TR.
I'm struggling to understand your interpretation of "continuous". The motors I have encountered have a continuous rating, a five minute max rating (~125%) and a five second emergency rating (~160%).
I'll say again the technology is available. In my personal opinion the research into flux, isolation and thermal flow modelling over the past few years is exceptional.
So Crab, there is an ETR that can do everything your mechanical TR can do ( let's face it it would have to otherwise it wouldn't be flyable)
Disadvantages
Not yet certified.
Needs electrical source, changing the safety case for the EPGDS.
Advantages
Less installation constraints.
Simpler installation and maintenance.
Power sharing with other systems.
Easily varied rotor speed.
For a number of years I looked at a variable speed tail rotor, but mechanically the penalty was just too much. The ETR changes the equation. ... I admit that I don't know whether it changes it enough, time will tell.