I purchased the high end $1700 version of SP4 in December. It is small enough for me to take to everywhere; like I am carrying a notebook. It is one of the best purchases I have made. I am almost never without it.

I'm a developer. For most of my career I wanted the top of the line workstation with dual socket xeon boards to do my work. More and more I find that unnecessary, for a number of reasons; one of them being almost every stack is getting lighter weight. Even Java EE containers spin up quickly. Still, I want as close to the experience I had with custom built Xeon workstations, and still be mobile. Laptops just aren't mobile. Also, it is mildly embarrassing to pull out a monster windows laptop in public (while everyone cooler than me clicks away on their mac). Plus, giving up any power for limited mobility isn't worth it for me. The convenience of using the SP4 trumps any limitations. The only limitations I can think of are screen size and resolution issues when attaching external monitors when at home. Otherwise, I couldn't be happier with it.