I've carried a laptop back and forth to work every day for 6 or 7 years (often via motorcycle.) Up until last week they had all been 15 or 15.4" machines. I can tell you that living with a 17" like the E1705 requires a certain degree of commitment.
You will need a big bag to lug this machine around. It's heavy enough that you'll probably want something more comfortable than a briefcase/folio type bag. I'm using the ViperXL bag by Booq. It's a very nice, very comfy bag... but the damn thing is so big, that I feel like an astronaut suited up for a EVA mission.
There is nothing subtle about dragging this machine around. I plopped the E1705 on the conference table during a meeting this week, and the meeting came to a screeching halt. I had to field a lot of questions before we got back on track. My machine dwarfed the many 15" Stinkpads in attendence.
I honestly believe a 15.4" laptop is the biggest you can go for a daily commuter, unless you have a good reason and can live with the size of the 17". Mine is for development, and for me, screen real estate is everything. It isn't going to be fun dragging it through airports, but I'm willing to pay that price. What's really nice about the E1705 in particular, is the construction. It is really rock solid. My WUXGA D800 Latitude (in theory a more rugged business class laptop) was much more flexible and creaky. The metal E1705 is a tank. I love it. WUXGA is a lot nicer at 17" too.
I love my new E1705, it's a good compromise for what I need it for. If you can live with a desktop replacement, this is a hard machine to beat. But if I had a different job, I'd probably be wishing for a sub-6 pound 14 or 15 machine.