Any guidance on how amount of weights lifted on a Hammer Strength bench (upright, not their flat model) correspodence to lifting plates with a 45 pound bar on a regular flat bench.

Am currently without a lifting partner and am considering switching for a while from regular bench to upright Hammer bench, but don't know how to account in figuring total lift for the lack of a bar.

Am sure this is confusing, but hopefully I'm making sense. In other words, I know a 225 bench with a bar is 4 45 plates and the 45 pound bar. What's a 225 bench on a Hammer? 225 worth of plates, or do you allow something for the weight of the handles?

A second question - any insight as to whether the flat bench with barbell is better/not as effective/less effective than using an upright Hammer bench?

Thanks for your insights.