About the PS2 game: it's worth adding that while RS2 is better enjoyed without guides or the internet, Minstrel Song is extremely complex and REQUIRES external help to be properly enjoyed. Not to the point of being unplayable like U:Saga, but close.
MilkBeard : Unfortunately, all characters take roughly the same time in RS1. They just have a slightly different starting point and quest. The difference is that, while there's no real NG+, continuing on the same save data allows to gain progressively more crystals, so each new play through becomes gradually easier (I think the crystals you get increase with the amount of quests you have finished, and this number is the only thing that's brought forward). Also, starting on the second play through, you unlock a new character to hire that's slightly stronger than the others. Nothing major unfortunately.