It will take a while to get your "bent legs" because the bents use different muscles or muscles differently. Get as light a trike as you can afford. For city riding I recommend one with a higher seat angle/better visibility. It can be very hard to see around parked cars at intersections if you are down too low. I ride in traffic and on MUPS constantly. A slightly more upright seat angle improves visibility and more than offsets the slight wind resistance imo. Ymmv. I have e-assist but I often see recumbent trike riders on my regular rides without assist and they are having no trouble keeping up in groups - but I"m sure they have been riding long enough to reset those muscles. So - at first - you will be slower.