In any case, there are no significant differences between this variant and the basic machine bench press. (bodybuilding-wizard.com)
McCaw et al. (1994) compared both barbell bench presses and smith machine bench presses with 60 % or 80 % of 1RM. (strengthandconditioningresearch.com)
Scientists from the California State University at Long Beach examined the amount of muscle activation that occurs when performing a barbell bench press versus a Smith machine bench press. (ironmanmagazine.com)