Z2 (Z226) vs. Zenbook UX-31?

I'm looking to pick up a 13" i7 of 1600x900 resolution or better, pretty much just to mess around with since my present resources already meet my needs. Two specs that would sell me on one model or the other are weight and battery time, but it seems that about 2.5lbs is about the best you can do across the board, as is a 7-hour rating for the battery. I like my 11" Zenbook well enough, and was thinking I'd like a 13" Zenbook UX-31 just fine, but before I buy that, does the Z2 (Z226 with 256GB SATA III at my local store) offer any real advantage over the Zenbook? The Z2 is a half pound lighter, which would make the choice a no brainer, but my local price on the Z2 is $1966 (with the PMD and slab battery another $500 and $200); the UX-31 is $1500. The weight does matter to me, and even though I've mostly adjusted to the Zenbook's keyboard, I agree with most people that it's still annoying. So does the extra $500 buy me anything more than a weight improvement on 13" and a more tolerable keyboard? And I'm not sure the Z2's full voltage cpu will make much difference to my computing experience--I don't do any gaming. Having the option to purchase the PMD and battery are an advantage over the Zenbook, but I don't think I'd ever want either accessory enough to purchase even if discounted 50%. It comes down to whether the Z2 presently offers an improved computing experience, or whether I'm better off just toting my 11" 2.5 pounder around for 6-8 more months to see if new models will give me more value (in terms of weight and/or battery time) for the $500 premium I'm willing to pay Sony.

All opinions and recommendations are welcome.

 

I believe the full voltage processor and the screen are worth the money!

 

I don't know if the Zenbook uses Gen3 SSD's like the Z2, but believe me, they're fast!

 

My SSD's are SanDisk, and people always say they're slow as SSD's go. But in terms of things I actually do with the computer, I don't experience any kind of unacceptably lagging performance. The UX-21 plays HD videos quite beautifully on the external HDMI monitor. Oddly, though, I have some SD video that the UX-21 won't play, but that do play on a non-ultrabook i5 (full voltage) ASUS laptop--could be a codec issue, not a cpu issue. But when it comes to web surfing and word processing, playing media, is added computing power or disk speed going to make a difference that matters? I already have 2-second resume, so would cutting my boot time from 22 seconds to 18 seconds make any difference? That's why I'm more into looking for improvements on weight (I walk 1-4 miles every day), and battery time (8 hours of solid battery time would free me of battery paranoia).

I do have a bunch of video editing coming up for the next three months, but even with that it's not enough that added computing power would save me that much time over what my UX-21 can already do. If I buy a new toy now, it's no problem, and I'm sure I'll appreciate the improvements. But if IB offers game changing improvements in battery time 6-8 months down the road (or decreased weight from shrinking the battery to match IB's lower power needs), I won't have the option at that time to buy another $2000 computer. On the other hand, I don't want to later regret putting off my instant gratification now, only to find that even a year from now there's still been no big improvement in ultrabook weight or battery performance.

 

I bought the mf.