They are reliable...

They are less reliable than alternators. Alternators have solid
commutators; generators have segmented ones - that's how a generator
makes DC. No diodes. Those segmented commutators cause arcing, and
that tends to foul them, get crap between the segments, etc. No big
deal to polish, but not fun either. This goes double if a bit of oil
that leaked from somewhere gets in there.

They don't go overvoltage and fry your radios like an alternator can...

Not true. Your generator can indeed go overvoltage. All it takes is a
failure in the overvoltage cutout on the regulator, or a field short to
ground. If the latter, the field switch will not be able to take the
generator offline. In fact, NOTHING will take it offline short of
pulling the breaker.

On top of that, even pulling the breaker is not a solution when you're
dealing with paralelled generators (and you are). That paralelling
relay system was developed for tractors (so there would not be a need
to built a very few expensive custom oversize generators) not airplanes
(with redundancy in mind). The failure I described (field short to
ground) is one that will take down the entire systems (as the
paralelling relay attempts to balance loads) and really hurts the
redundancy aspects.

Yes, they make less volts/current at
idle and low rpm, but you don't have to have everything turned on until
you roll onto the runway for take off...

Personally, I like to have all my avionics tunred on and set up when
launching into IMC, but that's just me.

In any case - I used to have all sorts of problems with my generator
system, to the point where I kept a spare generator on the shelf. Then
I replaced the 1930's-design vibrating point voltage regulators with a
Zeftronics set ($500 or so for the pair) and all the problems went
away, just like that. On top of that, the system is truly redundant
now - the regulators talk to each other and balance the laod based on
current, not voltage. If one is offline, it can't take down the other.

I suggest that as the real fix - I've had experience with the InterAv
conversion as well (friend had it on his PA-30) and was NOT impressed.
It too is a non-redundant system (master contactor failure takes down
the whole thing). The ideal soluteion would have been a truly
redundant alternator system. I understand Zeftronics was working on
that a couple of years ago - maybe they have it available now. I've
certainly been way more impressed by their stuff than anything InterAv
ever did.

Michael