Miscellaneous laptop discussions forum: Laptop ultrabook or any lightweight laptop - advice needed?

I want to buy a laptop, but I'm very confused! I'm a web developer, and I use my PC for: - email (Thunderbird), lots of browsing, FTP, Firefox/Firebug plus several other browsers for browser testing, Photoshop, Windows 7 and Microsoft Office.

I've been really tempted by the lightweight models such as Asus UX31. The Toshiba models are more expensive but also look good:

Asus UX31 - all in all this seems great, higher resolution, the the big flaw that CNET reports is the keyboard/trackpad not being very usable/comfortable over a long period of usage (i.e. hours). Has this been fixed or is this still an issue? (I seem to find reviews only from 2011 but the models continue to sell as the top choices today).

Toshiba Z830 (1.1kg) - core i5 1.6Ghz, 128Gb SSD hard drive, 6gB RAM, Win 7 Professional, free external DVD drive.

and a higher spec, heavier but still lightweight model: Toshiba R830 (1.4kg) - core i5 2.5Ghz, 500Gb SATA hard drive, 8Gb RAM, Win 7 Professional, dvd drive internal - I read some random reviews on this and it seems good, but some say that they can get much cheaper brands for the same spec, but at a slightly heavier build around 2kg. Also I read that the battery life is not so good, not sure if that's correct.

I'm confused because the ultra-lightweight Z830 model seems great to me, but will it run Photoshop and my other (above) applications well? On a desktop level at office, I use an i3, 2Gb memory (but probably will soon need an upgrade), and the hard drive space is probably enough at 128Gb, but of course the more the better. However, if I get a laptop, I still plan to use my desktop at office but use the laptop from home (evenings), weekends or when travelling once in a while.

OR see my questions about the UX31 above.

If the laptop were that powerful for my needs, I would simply hook it up to my external keyboard, monitor and mouse at office, and give the PC to another member of staff, thereby using the laptop permanently (one machine only, work and home).

My BIG question is, the price is the same for the above 2 models, and cheaper for the Asus..so do these specs match what I need? Does it make more sense to get the R830 since it's better spec, or does the SSD Z830 sound advanced as it is? I'm not sure if the SSD lighter hard drive would be an issue in the long term, or if the performance isn't so good, but if the R830 reviews arw NOT that good then I of course prefer to go for the lighter weight model Z830. I'd just like some opinions and advice urgently to help me make my decision

Many thanks!