I only played Toreador and Malk so far and I always went ranged in the end, with book useage and after I finished maximizing melee.
Its especially useful:
1. Against LaCroix. Get the big sniper riffle and ranged 10 (with the adv fan patch, you can get your last book in this level). You can hide behind the protection, get out, shoot him for insane damage into the head, then go back to hiding + reload (you might have to abort the automatic reload first to be able to move, otherwise Bach will shoot back and that hurts. A lot). IIRC you need 3 or 4 successful hits and you wont have a scratch on you afterwards.
2. Against Ming. Emptying the machine guns on her with Celerity 5 + Presence 5 + Auspex 5 = pure joy.
These are two of the hardest battles in the game and they turn downright trivial with ranged.
Its also useful at other places, of course, but for these two its especially crazy how well it works.