Except for web development. I can't imagine sitting at a laptop writing code compared to dual 24" monitors.
I can agree about your spec on PC's. I'm still running a 1.7 processor with 4GB of RAM. I just upgraded to WIN8 and have been surprised with its performance. With 7, no way I could have PS and Dreamweaver open at the same time. Now, I can run both with no issues, and the only thing I changed was upgrading to WIN8.
I'm also about to build a PC from scratch and have found the prices for fairly high end parts is coming down drastically. You can get a totally loaded system (Intel Core i7 processor, 16GB RAM, 2GB Video card) for well under $800.