I'm a 65 yr old casual bike rider. I exercise regularily and I like to ride casually on hard surfaces. I have no interest in trail riding. I only recently looked into ebikes and decided I like the looks of the Trek Allant series. The specs tell me the difference between the 7s, 8s and 9.9s. Given that I am not a hard core rider, would I notice the difference between the three models for casual riding? I like the looks of the 9.9s best. If you ignore the cost, is the 9.9s that much better than the 8s? I don't want to buy the 7s just to save money if the other two significantly out perform. I am willing to pay if performance and durability come with the higher prices. I would appreciate any thoughts or opinions. Thanks.