Do you mean the Dutch Gazelle range? I have no experience of any ready-made electric bikes although I did once fit an after-market electric conversion kit to my wife's hybrid and it was very effective.
Looking at the specifications for the Gazelle I see that some have the motor mounted in the front wheel and some have a crank motor. I think the consensus opinion is that the crank motor system is better because it can take advantage of the gears, whereas a wheel motor cannot. Most of them seem to have hub gears which means less maintenance.
The only thing I don't like is that most have rim brakes. Rim brakes are certainly powerful but they eventually wear the rim out. How quickly this happens depends very much on how many steep hills you go down! But eventually the wheels will need to be rebuilt with new rims. I'm surprised they don't fit discs or, in keeping with the low-maintenance ethos, roller brakes.
I did a quick Google and found this:
www.50cycles.com/electric-bikes/kalkhoff-bikes/integrale_i8.html
It's quite a bit more expensive but you get what you pay for, and the specs look good - Crank drive, hydraulic disc brakes, 8-speed hub gears, integral lights, and Gates carbon belt drive (so no oily chain to maintain).
I think you need to set aside some time to visit suppliers and test-ride a few bikes before you decide.