I wonder if anyone can give me some advice on the benefits of the 8 over the 3. I'm thinking this may include hill climbing ability , which is something I'm really keen to be as good as possible .
I may be able to help as I faced almost exactly that choice. I had more or less decided on a step-thru Kalkhoff or Dover. I had a test ride on an older Agattu (only 7 speeds) arranged by 50 cycles with one of their previous customers who was acting as a demonstrator. You can arrange to meet a demonstrator if there is one nearby or perhaps even have a bike sent to you for a test ride through their
web page.
I then saw the almost identical Dover 8 speed model in a local shop, but it was more money. Since I felt I did not need the back up of service from a local shop I decided not to pay more money for a Dover.
Next, I saw that 50 cycles was selling a even cheaper option - a 3 speed Agattu with a small 8Ah battery. Attracted by the lower price I travelled to their Richmond showroom to try it out. I was particularly interested if to find out if I was strong enough to pedal it up steep hills. I was and I surmounted Nightingale Lane a couple of times see my
test report. 5.6mph up a hill averaging 12% gradient. This was good enough for what I need.
When I ordered the bike I had the 8Ah battery swapped out for the 18Ah, since sometimes I need to ride over 30 miles. The batteries are in identical cases, so as the swap works for the Kalkhoff Aggatu and I can't see why it would not for the Raleigh Dover.
To return to the gearing, I bought the 3 speed to save money and it is fine for me and my hills. If you are weaker and heavier than me (93Kg), and have hills over say 5% you might want to go for the 8 gear. In 2 months I have improved my stamina quite a bit, and last Saturday I flew up a 5% half a mile long hill at around 14 mph in top gear with no need to change down, so I am very well pleased with 3 gears for my locality.
The other thing to consider is your required maximum speed. Except when I am on a "mission", I am actually completely satisfied to be trundling along at 10-12 mph. If I was commuting and always wanted to pedal near and above the bike's assistance cut-off speed, then I would definitely advise getting the 8 speed which will bring down the pedal cadence rate in top gear.
I measured the 3 gear ratios on the Agattu and reported them in
this thread.
I will be in Leeds at the end of the month with my Agattu (on some hills), but I suppose that will be much too far for you to travel for a try out.
