In general, about weight, I agree. One exception is rotating mass (i.e., wheels). A light, well-built wheel handles a lot better than a heavy one. No amount of personal weight loss is going to make up for that.
Beyond mass, the behavior of shifters and brakes on nice bikes is much, much crisper and more predictable than on cheaper models. They also have better capacity for tuning (e.g., to eliminate chain rub, or accommodate a high-range sprocket set), and are more likely to stay in proper adjustment for longer. This makes riding a lot more fun -- the machine is very responsive to your wishes, and you forget it's there.
You probably are aware of this, but I felt a need to mention some of the advantages of a nice bike.
Beyond mass, the behavior of shifters and brakes on nice bikes is much, much crisper and more predictable than on cheaper models. They also have better capacity for tuning (e.g., to eliminate chain rub, or accommodate a high-range sprocket set), and are more likely to stay in proper adjustment for longer. This makes riding a lot more fun -- the machine is very responsive to your wishes, and you forget it's there.
You probably are aware of this, but I felt a need to mention some of the advantages of a nice bike.