@GeorgeGee I think you misread or skipped the last paragraph, but you definitely misinterpreted another part of my answer. When I said ”I don’t see four pounds as heavy.”, I was referring to my laptop which is listed at 3.88 pounds and yet still has the power to run Photoshop. See, CPUs don’t speed up with larger screens; processing power remains constant while weight increases dramatically and battery life takes a nose dive. Meanwhile, 3GB of RAM is still 3GB, and hard drives don’t magically expend either.
Therefore, I refute your claim that “A laptop powerful enough to run programs like Photoshop well will tend to be heavy…” since I can run it fine on mine, and there are 13” Core i5s out there that can do it better while still being lighter than most 15” laptops.
Since the OP was asking about laptops I feel it safe to assume that they want something that weighs less than 9kg not counting screen, keyboard, mouse, or the long extension cord you need to go anywhere with it so I disregarded desktop systems even though they generally are considerably more powerful and capable at the same price point.
My T135 with 3GB RAM, a 320GB hard drive, and no optical drive cost the same as my i3–530 tower with 6 GB RAM, a 1 TB drive, and a DVD burner. Another $100 got me a silent GT240 card that beats the shit out of the T135’s non-upgradable Intel GMA4500M. Still, my T135 is more portable than even the LCD monitor on that tower so it depends on priorities.
And you’re right about the CPU, but how long will that i5–650 last with a 5.6 amp-hour pack? Sorry, but the Core i-series was designed for speed and power with little concern about power consumption aside from the linked issues of heat dissipation whereas the SU4100 I have and the T4400 were designed with a different set of parameters. A CPU that draws 73W will suck a battery dead in half the time of one that draws 35W, which in turn will drain a pack far quicker than my 10W CULV CPU. That is comparing apples and orangutans, my friend.
We do agree that certain things (like Photoshop) are better suited for a more powerful system with a larger screen though. I don’t see either of those two as being appreciably more capable of Photoshopping than my T135 and would take my cheap-ass tower over either of them any day if I were serious about Photoshop. You might be correct in that they just want a laptop since laptops are “cool” without realizing how much less capable they are (on average) than a desktop system. And you are definitely correct that a 24” screen is better for that sort of stuff than a 15 one.