OP here.

Thanks for a very useful discussion. I conclude that - horses for
courses - a cordless isn't the horse for my course [yet].

I do have a small (40cm) B&D cordless which is now about 5 years old.
With the enormous strides in battery and other electronic technologies,
I wondered if they now make a cordless which combines great power with
lighter weight. It seems that they don't.

Thanks a lot for all the opinions!

John


Postscript of dubious value:

My particular "course", as I said in the post, is that I do *a lot* of
hedges: I cut the hedges in three gardens (mine and two others); the
total length must be about 200 yards, counting two sides in a few cases;
the average height overall is over 6 feet. The hedges are [thinks]
cotoneaster, beech, hazel, [ivy], hawthorn, blackthorn, and the damned
holly (which must make up half the total: what a ******* that is to
trim, especially when you're half-way up a ladder).

Going up (and down) the ladder, is the worst thing, these days: joints
and legs.

All these hedges are very mature, and therefore have thicker branches to
cut at intervals, in different places. Hence, I chose a cutter which
has a wide tooth spacing - 26mm in this case. Even when the branch is
somewhat thicker (within reason), sawing at it with this trimmer will
deal with it.

As I said, it's a Bosch 55-26 - 55cm blade, 26mm tooth spacing. Also as
I said, it "blazes" through all this hedging. I only cut most of the
stuff once a year, but in my own garden I do some every growing month,
the rest just twice a year. (And always outside the nesting season of
course.)

From the discussion, my gut feeling was right: nothing compares to mains
power [coming into a powerful cutter].

Of course a 4-stroke petrol would be more powerful (and free of those
reels of cable), but my work nowhere near justifies that kind of cost.
Furthermo even a 4-stroke is noisy, but a 2-stroke is absolute hell -
for the user, and for the neighbours. I have never considered using a
petrol cutter.