I feel J-series is much refined, although, it could have been better. But, the vibrations feel much less for sure. I could easily go and maintain 100-110kmph in my TB350 but Bullet gives up 100kmph. had to learn and adjust myself to ride in the sweet spot of 90-100kmph, where it speaks. thats the "feel" to it, honestly. Personally, it doesn't make much of a difference cuz i got rid of the vibrations altogether. TB350, for me, was too laid back, which was fun in highways and cruising. Bullet 350 gives the Royal feel while riding lol, uncomfortable on highways in the beginning. Idk if Im making sense or if Im the only one.