I've never seen much point in online dice rollers - IME it goes a lot smoother if the GM does all the rolls. I also think online play works much better with less reliance on dice. Outside of combat (for combat games), I find GM discretion is the best arbiter of whether the PC can climb the wall, sneak up on the guards etc - with reference to the PC's skills of course. I only roll if it seems uncertain to me. Of course I'm far more likely to 'arbitrarily' let the PC succeed than have them arbitraily fail. Online games are great for immersive roleplay but are not good for tactical combat, so they favour a more story-oriented approach than a tabletop game.