The JaxJox KettlebellConnect 2 is the winner due to its smart features and wider weight range. According to a review by Wirecutter, the JaxJox KettlebellConnect 2 is 'one of the most versatile and convenient kettlebells on the market'. However, the Bowflex SelectTech 840 is a more affordable option with a space-saving design, as noted by a review by CNET.