i love my summit viper. just ordered a summit razor ss. it has no front bar like the bushmaster - but the most important thing is it has the comfy seat, unlike the bushmaster. i haven't sat in a bushmaster so i'm just guessing here - but from the looks of it i'd guess that about 1.5 hours is all i could take in a seat like that. looks similar to some hang-on stand seats i've used that just killed my back.