Its been too late for me to reply on this query, but have ownership experience of both the scooters infact my sister owns Activa 3G & I use Jupiter. No doubt Honda has its very strong brand name so they really don't need to try that hard to convince a customer to buy their product. I believe Honda Activa sells more than 2lakh units while TVS Jupiter is the second best selling with approx. 55-60k units.
My personal experice is too bad with Honda, I felt at the showroom or at the service center they don't care much about their customers. As if they are doing some favour on us by selling their bikes or by servicing.
On the contarary at TVS I had pleasent experience at the time of purchase and even during after sales. I am truly pleased with my purchase decision. Kudos to TVS for bringing wonderful product and providing top class service.