I dunno, giving someone a class which requires loads of system mastery to make work well doesn't seem like a nice thing to do to a newbie. The big benefit of the PoW classes is that they pretty much all give improbably rapid reloading, which turns guns from basically not viable into, well, bows, but bows which target touch AC (which is pretty potent). If you're OK with using alchemical cartridges all the time then it's not such an issue but even just knowing that you need to pay all those feat taxes isn't something you'd expect of someone who's never played the game before.
A lot of this depends on the game, the vision for the character, etc, but as to the question of which class is "better" or "stronger", the PoW classes are definitely the latter and arguably the former too (they're slightly less well-written and polished and suffer from a lot of feature creep, but most importantly they have more options and are therefore - subjectively - more fun, and probably a smaller proportion of "trap" options to catch out newbies, too).
A lot of this depends on the game, the vision for the character, etc, but as to the question of which class is "better" or "stronger", the PoW classes are definitely the latter and arguably the former too (they're slightly less well-written and polished and suffer from a lot of feature creep, but most importantly they have more options and are therefore - subjectively - more fun, and probably a smaller proportion of "trap" options to catch out newbies, too).