It's pretty much been summed up, but ;
S&W: better out of box trigger, generally a prettier gun.
Ruger: tougher than just about anything else on the market. Trigger needs work out of box (best trigger job for a Ruger: get a set of snap caps, and dry fire it 1,000 times, slicks right up).
As for S&Ws being weak, other than the whole forcing cone issue on teh K-fram .357s, there isn't much to this one.
S&Ws are produced to handle standard loads (and for loads have have a +p rating, for +p). With S&W stick to Federal, Winchester, Remington, Hornady and Speer, and you'll be just fine. Buffalo bore and Garret warn against using their ammo in S&Ws because it's loaded above SAAMI-spec.
Rugers, on teh other hand (except the new Vaqueros) are proofed at 30% above SAAMI-spec. That's why they're so tough.
So really, it isn't that S&W makes weak guns, but that people have gotten so used to the tanks that Ruger builds that most (if not all) other makes LOOK weak in comparison.
Oh, yeah, BTW, I like 'em both. S&Ws tend to be my carry guns, Rugers go hunting (I like the loudenboomer loads for hunting).