Yes. Not only are they usually lighter, but they lighten your wallet too for a more impressive weight savings.

Sam's premise is too simplistic. The geometry of a bike is not static when it's being ridden and his "premise" (which is impossible to be a premise, as his "premise" is the very notion in contention) is true sometimes and not true at other times; kinda depends on what kind of frame we are using and what kind of components we are using. If the "frame material" true believers are misleading, so to are the "nothing-matters-everyone's-misleading-you-buy-the-cheap-frame" true believers. As per usual, when you have an argument between true believers, split the difference and you aren't too far off the truth.

The difference between "name brand" and "generic" frames is that the name brand frame manufacturers generally know what they are doing, engineering wise (they innovate, do research/development, etc.), while the generic brands copy the name brands. The name brands tend to specialize in certain things. Cervelo has made a name for itself in aerodynamic design of their frames. Trek, in a comfort/stiffness/geometry blend to fit stage racing or sport touring. Others, like my team's sponsored frame, Velo Vie, specialize in stiffness and light weight. Generic frames, on the other hand, are designed to be cheap while retaining a sufficient level of performance.

Nothing wrong with either business model. I mean, really, the generic frame manufacturers owe their existence to the name brand frame manufacturers and lots of casual roadies and budget racers ride generic frames. But generally, if you want cutting edge, buy name brand. If you want value, buy generic. Kind of like pharmaceutical drugs.

No two people are the same. Take the same frame with two people of the same height and weight and put them on the exact same bike. One may love it the other thinks it's a noodly pos. The point is you are asking a very ambiguous question regarding a frame. There are just too many factors to consider and get a promising answer from anyone else other than your own personal experience. Just ride as many different types of frames possible.

For instance, I rode a 09 trek 2.1 triple up a mountain in my area 54cm btw. It felt nice, decent shifting and all. Nice power responds and what not. That bike had far superior components for the most part and had more carbon fiber parts than the bike I have now.

I then went out and rode a compact double 09 allez, the very base model of the specialized allez. Took it up the same mountain, felt infinitely better, even with sora shifters I liked it over the trek. And that is what I ended up buying. Even thought the allez came with way cheaper parts I opted for the frame that felt better to me, even though on paper the trek should have felt like riding on a cloud compared to the allez but it wasn't.