Firstly, thanks again to all who replied with advice and information. It was
much appreciated.

I have decided that for my main intended purpose, - (through dovetails on
large boards,) the maximum width capacity of the Akeda would be a limiting
factor. In all other respects, it would do all I required and more.

I've decided on a "first generation" jig, primarily to accommodate wider and
longer boards. Similar to the one at this URL.

http://www.gifkins.com.au/

These are the pro's and cons as I see them at this stage:

Pro: Can handle wider and longer boards than many systems. Gifkens gives
a standard width/length dimension of 1m x 300mm, but states that
this can be extended considerably with care. I believe one
option would be to route with a hand-held for larger dimensions.
Can be used on a router table. (I have two, - can use one for
pins, one for tails.)
No bushes or adaptors required on router. (Router bits have
bearings.)
Excellent visibility.
Can do variable spaced dovetails (with spacer shims)
Simple device and intuitive setup and operation.
Australian manufacturer. Spares should be easier to source.
Templates have tail and pin on opposite sides. Once the tails
are indexed, the pins are automatically indexed
as well.
Can do finger joints.

Con: More expensive.The Akeda would cost me almost $1000 landed here in
Australia. The Gifkens package with everything will cost me
around $1300 delivered.
Does not do half-blind dovetails.

Time will tell if I've made a good decision or not : )

Diggerop