As said, a quality cadence sensor, which the Wisper should have, is the best choice.
David Miall, the owner of Wisper and one of life's good guys, will give you all the info you need.
Worth giving him a ring before placing the order.
A rough yearly maintenance cost is impossible to give because there are so many variables.
As an example, an Eagle cassette is a minimum of about £140, and you can pay as much as £300.
The Sunrace cassette on the Orbea is about £70.
That differential may be repeated elsewhere, although you...
A track bike chain tensioner might do the job.
They are designed for horizontal dropouts, but may stay in place on other types of dropouts when tightened...
The Cube does have a better spec on paper, but the Orbea might be cheaper to look after.
Replacement parts for the Cube's Sram Eagle groupset are very expensive.
A consideration given that some mountain bikers seem to wear chains and cassettes quickly.
The bigger battery on the Cube is a plus...
From a quick look at the specs online, I think the difference is the Como has a much more set up and beg riding position.
The handlebars are swept back, and higher in relation to the saddle.
Stuff like tyres can depend on what the bike maker can get cheap at the time of the bike build.
You ought to get the model of battery and motor stated on the website.
But the 'specs may change' warning is there for a reason.
The dealer is doing you no favours here.
The likes of Shimano, Bosch, and Yamaha are all pretty much the same when it comes to power and weight.
You can get slightly more powerful versions of the Bosch and Shimano motors, but you may not notice any difference.
Three grand is a lot to take off...
You do not need an MTB for the off road paths and dirt tracks you specify.
Almost any ebike of reasonable quality will be well capable of those conditions, and in most cases, more suited to those conditions.
If you fancy a Woosh, the Camino would do the job.
About the worst that might happen...
Gear range can be a weak point with hub gears, particularly those with fewer ratios.
The 263% from the Nexus 5 will be too narrow for a lot of riders.
At the other end of the scale you have a Rohloff - or a mountain triple MTB derailer gearset - with a range of about 500%.
I rarely use top...
I suspect the LCD display comment relates to kits with LCD displays being generally better than those with other types.
You will struggle to get a battery that will reliably do the 60 mile trip to London, so I think the only answer is to carry a spare for longer rides.
My bike has a twin...
Well done for producing what looks like an excellent bike for the money.
If I had under a grand for an ebike, a Rambletta is what I'd spend it on.
Shame you can't meet demand.
No reason why the next consignment shouldn't also sell well.
How about your Rambletta?
I'm a big fan of 20" wheel compact framed ebikes.
They do the job and are much easier to (wo)manhandle than big wheel bikes.
Nice and comfy on balloon tyres.
https://wooshbikes.co.uk/?rambletta
Did you see the charger, the battery, and did you see their other bike?
I'm afraid it still sounds fishy to me.
The guy's nicked the bike, found out already it's all but unfixable so is prepared to let it go for whatever he can get for it, in this case fifty quid.
The fact that it's brand new...
Where are you?
Due to a persistent medical problem, my Supercharger Rohloff twin battery could be for sale - it's the bike in my avatar.
I'm having trouble mounting a cross bar so am looking to change to a step through.
The 20" ebikes are much easier to handle than the full size wheel ones and they are easier to ride.
Such an ebike is an ideal, I would say only, choice for the OP.
This leads to one bike only given the budget and current availability of ebikes - a Woosh Rambletta.
Apart from anything else...
Standard Chinese ebike - I've seen worse.
Separate battery and controller is a scruffy design.
For that budget I'd ring woosh and get them to recommend a bike from their range.
Proper after sales service, too, making woosh hard to beat for the money.
The motor is quite pokey.
I thought it had a bit more grunt than my Bosch bikes.
Some owners have got 24/25mph out of them, but I suspect you would need to be fairly light to get that.