David, since you are living in Europe (I've read on your system page that you
are living in England) it should not be that difficult to find a demo model. For
example, in the Netherlands there are currently an E-350 and also an E-450
advertised by dealer on www.hifi.nl (look in the "tweedehands" section). Check
also www.audio-markt.de, (with a little patience) one can find pretty much
any Accuphase model on this site. Germany is the number one importer of
Accuphase units, they have great respect for Accuphase (which says a lot
about the brand).
Regarding the E-307 integrated, I would say it is a bit too old (10 years or so).
For a couple of hundreds more you should be able to get an E-308 (the
predecessor of E-350). However, since currently you are driving your speakers
with a small tube amp, I would advise you to go for an E-550. It has as much
power as the E-308 and E-350 integrated amps but sounds better and also
copes better with difficult loads. If you need/want more power then go for the
E-408 or E-450 (of these two I would pick up the first one).
Dave, not much will be achieve by calling Accuphase in Japan and complain
about their dutch dealer. My feeling is that the importers are required to
behave that way (I've understood that the German importer behaves similarly).
From their perspective Accuphase is not like any other brand and hence is not
for everyone. They will be polite with you (if you look decent) and just order
products without much concern for the price. This is usually the case
with most luxurious brands/shops. (Of course, dealers do not behave like
that, they are always happy to sell an Accuphase.)
Paul