Ragging is not the correct term but I understand what you are getting at. I had a 13 inch and I loved it. I have a 15 inch and I love it. Before, the 13 inch's greater portability and lower price worked better for me. Today, the 15 inch's larger screen and quad core CPU work better for me as the tasks I do today are different than those I did yesterday.
The 13 and the 15 are very different beasts. With that said, the 15 and 17 are very different beasts as well, despite their hardware similarities. Those working certain datasets, rendering, designing, editing, etc. with programs that are optimized for quad core CPUs can see a substantial performance over a dual core CPU. Also, the 15 inch's screen works better for the work I do now.
Now is there anything wrong with the 13? Absolutely not. The 13 inch outperforms the previous flagship 15/17. The dual core SB is plenty fast. Even the older C2D MBPs still will perform just fine for most users. My brother has the most recent refresh and it is not a slow computer by any means. It is even more awesome than my older C2D model was. However, he moves around more than I and so the smaller form factor fits him better. He also does less resource-intensive programs than I and so the CPU difference between the 13 and 15 are really unimportant, but with the programs he DOES use, the difference between the 13 MBP and MBA is important. I can't speak to gaming as neither him nor I play games on our machines but I imagine both do well for what they are despite neither being made as a 'gaming' laptop. For my mother, all of the MBPs are unnecessarily large as she only uses very 'light' programs, never uses the ODD, and favors ultra portability as she is on the go...and so for her, the MBA fit the bill perfectly. My father hates laptops all together and so none of them work for him.
Ultimately, there is no such thing as a better sized MBP. There is only better relative to an individual user's needs.
