While the models you listed are nice, the longer you wait the more you get in your next model.
Good to read you follow the ABC rule (always be charging) since that saves your battery for times you really need it.
I have a 4 and half years old thinkpad X201 tablet... the processor is i7-620lm. After I replaced the HDD by a SSD, and put a pair of 4G RAM inside (so a total of 8G), it doesn't bother me in the everyday use ever.
I also put new heat sink and paste to solve the overheating problem, and bought a new battery on ebay last year. The new one can hold up to 3 hours. It is not impressive using today's standard. But I rarely use it without the power cord.
Recently, I was tempted by the new macbook. The main reason is that I was always looking for a chance to try the mac OS, also the laptop is only 2 lbs. Honestly the only complaint on my thinkpad is the weight. It is more than 4 lbs with the new 9-cell battery.
Today I also saw the Thinkpad X1 deal... so tempted but decided not to buy it.
Anyway, I don't know if I should buy a new laptop... (and if the answer is yes, which one is better - bascially I was debating among X1, new Macbook, SP3 and new XPS 13)
I love my old laptop, and it is still good enough for my daily use (browse internet, document editing, watch movie/online video, and some engineering oriented programming such as MATLAB). But current laptops/ultrabooks are nicer, more powerful but lighter and can last longer.
I am always on short trips (driving distances) and the weight is not that a big deal but still bothers me a little bit.
Any opinion will be helpful. Thanks.