I am a Mac fan, but for me, OS X is no longer powerful enough for my needs, as I am working on a very specialized project that basically requires a Windows PC.
I have a Sony Vaio Duo 13" (top-of-the-line) slider notebook. I picked this notebook because of the form-factor. There are complaints about the WiFi on this computer, due to the Intel Haswell chipset, but this
should be resolved with a driver update (eventually). I have not experienced this problem, though. The writing is perfect in OneNote, but otherwise, the N-Trig digitizer (versus the Wacom digitzer) sucks, as there is no pressure sensitivity support from Adobe in Adobe software, such as Photoshop.
There are reports of a 20+ hour battery life on this computer, and even with heavy use, I get 10+ hours if I have brightness and battery settings set correctly.
By the way, HP notebooks are considered to have some of the worst failure rates in the industry.
http://www.squaretrade.com/htm/pdf/SquareTrade_laptop_reliability_1109.pdf (see page 6)
FYI, I worked as a computer repair tech for 2.5 years and I am an electrical engineering student, if that is of any use to you.
Thinkpads (NOT Ideapads) are typically really good. No matter what, try to get a computer with an Intel Haswell chipset (uses the 4th-generation iX processors), due to performance and battery life.