You mention the motor being clattery mine has been good even on very very rough terrain. As for difficulty maintaining 16+mph and without axsistance well being honest ive been out on mine without switching the motor on and going up hills etc and no real issue.
LF801.
I tested a levo nice bike and all but it didnt quite feel right, my normal bike is a fuel ex and fits good. I test rode a rail and the fit was good and rode really well. I too was torn over the 7,9 or 98 at a push the shop did me a really good deal and i got a 98 bike is good and i went...
I do know of someone who has bought a 9.9 rail and just rides it around the village and doesnt know how to use the kiosk properly and he aint a dentist but a bin man.