anything that would recruit more muscle and make an exercise harder will have greater benefit..i voted for seated BB front press only because ive never done them standing..which does not imply that seated is better just my personal preference
I do heavy, low rep standing barbell presses and moderate rep, seated strict dumbell presses. Best of both worlds. In my opinion it is easier to mess your back up doing seated presses than standing if you don't have back support while seated.
i like standing push presses, if i do db military its not heavy, its usually 8-10 reps, which i think is moderate.. seated military is where its at though. touching my clavical and exploding up i like using 4-6 reps on that
a couple years ago i woulda said seated db press
but to be honest, i have made some good gains doing push press
plus, i dont have a spotter i trust at this gym, and i think thats pretty important for seated db presses