I personally think AGS is a better choice, but thats mainly because I do not do much monster slaying. I usually just play bounty hunter or some other PvP option. SGS is overall better if your not a PvP person, it helps alot more overall on pretty much everything, training, GWD boss fights, or any other bosses for that matter. So my reccomendation is for you to buy a SGS and use that unless you plan on joining the Runescape PvP players, then in that case, i reccomend the infamous AGS.