This really depends on the speific application. This could also be impacted by the range of the scanner...If the pickers are on lift trucks, a long range scanner on the MC9x90 might be more efficient than an RS507. The biggest gains in a picking operation would be where the product requires 2 hands to lift individulal picks (example---a case of canned goods) Typically thr RS507 is used with a voice directed picking application on the WT40xx. The RS507 itself does not necessarily drive all  the productivity gains. Some productivity is gained by being "hands free" while other gains are related to the efficiencies of vouce directed picking.There is also a safety aspect where the operator of a lift truck is not reading a screen so he is a safer operator. . The voice  vendors in theUS will typically offer to do a case study at the site to show the specific productivity gains, but they typically claim about 20% increase in efficiency overall and are readily able to deliver on these claims