My bike odometer is showing 2000 kilometers. That's the distance travelled on my current bike - the motor with two gears. And I love it.
High gear lets me bowl along at about 25 kph (even faster if it's downhill), but I rarely go that fast. Caching is mostly over fairly rough ground, so I use low gear, which gives me lots of torque (pull power) and a top speed of about 18 kph.
It's supposed to run at 36 volts, so I'm using 12S Lipo batteries, which is 50 volts fully charged, 40 volts when near to empty. The extra volts give me a bit more oomph.
I mostly ride in top gear on the front gearwheel, and change the rear gearwheel according to whether I'm going along a good, flat surface; lower gears if it's rough or uphill. Exceptionally, I change the front gearwheel to give me an even lower gear, for going up steep slopes. Sometimes I get off and walk the bike, because although that's tedious, it's better than falling off!
I started off by using trios of 4S, 5AH batteries; now I use trios of 4S, 10AH batteries, giving me 12S, 10AH (50 volts freshly charged). That's normally enough for a morning's ride or an afternoon; 12 to 20 km. Then I like to get back to the car for lunch, and while I'm eating recharge the GPS. Then a fresh 10AH battery, and I'm on my way again. As well as the trio of 10AH batteries, I carry a trio of 5AH batteries, as a reserve, but so far, I haven't needed it.
I also carry a full bike toolkit (spanners, pump, inner tube, bike multitool, etc) and my full geocaching toolkit (pliers multitool, first aid kit, sting remedy, etc). I carry a hefty bike lock, in case I need to temporarily leave the bike where it might get nicked (that happened to me once, fortunately it was an ordinary bike) and a head torch in case I'm out later than expected. I also carry a hard drive (because I like to leave a hard drive as a swapsie in caches that are big enough and waterproof). But don't get too excited if you find one; half of them don't work at all, and the other half have failed and been reformatted, and I won't use them because they might fail again.
All this stuff is in a saddle bag, because it adds up to being pretty heavy. When I need to lift the bike over an obstacle, I can quickly take the bag off before lifting the bike.
On the handlebars, I have a lot of stuff. My PDA for navigating, of course, and the bike controller, showing speed, distance travelled and voltage. There's a thermometer to monitor the motor, and a little bell I can ting to warn pedestrians when I'm coming from behind them. And there's also a turn/stop indicator; that's usful whem I'm sharing a road with traffic, to let cars behind know that I'm turning right, or slowing down (the brake light comes on when I brake). It also gives me a horn to toot.
I do all the maintenance and repair - for me, that's part of the fun. That mostly consists of replacing brake pads, retensioning cables and oiling things, but I've also needed to replace the rear suspension when it broke.
Here's to the next 2000 kilometers!