£300 to £400 more doesn't give many more options in crank drive bikes, and I'm sticking to recommending crank drive since I know that's what you are used to and realise just how very hilly your area's roads can be.
There's the Tonaro models from
Powerpedals at between £1150 and £1290, but they are often rather heavy and will seem rather different from your Lafree Twist and predominantly throttle controlled. Rival company CycleZee also sell two Tonaro models at a lower £925 retail price. You won't find much choice in crank drives locally in the Bristol area, but Powerpedals are in South Molton, Devon so not a million miles away. CycleZee are only at Milton Keynes. Woosh are only at Southend or Cambridge.
Those give you a clue of one reason for the pricing variations, bikes sold through cycle dealers are of necessity much dearer since the dealer needs around 30% or so margin to both stock e-bike models and provide ongoing support to customers buying them.
Paying from £1799 gets you one of the AVE German made e-bikes using the superb Bosch crank drive system which will have all the sophistication and more of your old Lafree Twist, and with much more power. These are imported by
EBCO and sold through dealers as well. They are also sold by three cycle dealers in Bristol which you'll see under South West on
this EBCO webpage. The much higher cost of these bikes is largely in the high quality European manufacture of bike and power unit and partly in having them available locally to you with support. Check with those three dealers before travelling to see if any have AVE models in stock to see and try.
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