Not for the stuff I do.

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Im thinking of bleeding edge in a more holistic sense. ;)

Lenovo X-series are great for a full-featured laptop in a miniature package - X201 is probably the best mix of high performance and small size out there, but the battery life is not comparable to a netbook or other lower-performing ultraportables (Core 2 ULV-based). HP also makes a similar, but rather chunkier, 12.1" i3/i5 notebook; I've only used it in-store but it seemed OK just not worth the money when the pricing was nearly identical to the X201.

Those use the regular i3/i5/i7 mobile versions. There are substantially lower-clocked and more battery-friendly ULV (ultra-low-voltage) versions although the i5 and i7 versions will reach higher speesd temporarily or when operating primarily on one core, with the "Turbo Boost" feature. There are not yet many notebooks using the new i5 ULV-version processors; when those become more common there should be a lot more options. Right now, the two models I'm aware of using these are the Acer TimelineX 1830T (the i3UM version is best avoided because of the lack of turbo boost) and the Dell Alienware m11x. I'd expect more of these soon.

If you need more power than a netbook, but don't need a full-powered processor, there are quite a few consumer-ULV (CULV) and business ultraportables using various Pentium Dual Core (SU4100) and Core 2 Duo ULV (SU7300 at the low end, SU9600 at the high) The new Macbook Air 11" is one such example, as are the Acer 1810T, Dell Inspiron 11z, Latitude D4200, etc. These are going to be a good bit slower than a regular Core 2 Laptop (and unlike the new ULV i5s, no useful turbo feature for occasional higher speed on demand) but are WAY faster than single-core netbook processors. The "Core 2 Solo" SU3500 is best avoided; it's not much faster than a netbook Atom processor.

There are also a few netbooks based on the dual-core Atom D510 and D525 processors (intended for nettop atoms) and on AMD Neo X2 processors (also dual core) - these should be much better than single core Atoms (N270/280/450/475) but with worse battery life; I haven't seen enough benchmarks or used them to really compare them fairly to the CULV Core2/Pentium Dual Core but among the more attractive designs and prices is the Lenovo X100e (the Dell m101z is similar but a much less attractive design.) Passmark is far from my favorite benchmark, but the AMD in the Dell (about 750) and Lenovo (about 850) is bit low disappointing compared to the Pentium Dual Core SU4100 used in the older Dell 11z and Acer 1810T (about 950).

One other option for battery life is to go with a conventional laptop with an extended battery; it used to be possible with many models to swap out the optical drive for a 2nd battery - I'm not aware of any model that still allows it that, but quite a few business-line models have some other secondary-battery mechanism (for example, a "slice" which fits under the machine on some Dell models.) This tends to remain quite compact, but adds a good bit in weight, so it's not a good choice for those who are weight-sensitive.

Z series is 13 inches, not very tiny. big enough to work comfortably and small enough to fit in most places. With SSD, i7, 7 hours battery and 3 lbs. its not bad in terms of ultra portables.

My little Eee PC 10 inch with 6 cell battery and Atom processor runs a good 9 hours +. It is about the smallest keyboard that I am comfortable typing on - about 92% normal size. I have had the 7 inch Eee (use it for a Slingbox server at home now) and it was simply too small to touch type on.

I use the 10 inch Eee for all sorts of paperwork while flying. It is very light - I think about 2 lbs.

Lightest and coolest looking is the MacBook Air, but battery life is kinda crappy for the price.

I'm getting about 5 hours out of my X201 wifi browsing in lounges.

I've watched films inflight for > 2hrs, but didn't note the battery start/end state. (Films ripped and on hard drive)

Which battery size do you have?

Lenovo is actually claiming 6.7 hours for the 6-cell and 11.3 hours for the 9.

My main experience with the battery life on it has been second hand with colleagues going from the Dell D430/E4200 to the X201 (although the general impression is that it's an otherwise all-around-superior machine, except for batter life.)

Sony's premium computers in the sub-notebook category (<14") are (for the US market):

P series - 1.3 lbs, 8" 1600x768, Atom Z530/Z540/Z550/Z560 1.6/1.8/2.0/2.13 GHz, 128 GB or 256GB SSD, 2GB RAM, 5 hours battery life
X series - 1.6lbs, 11.1" 1366x768, Atom Z550 2GHz, 2GB RAM, 64 or 128GB SSD, 3 hours battery life w/ supplied compact battery, or 12 hours w/supplied high-capacity battery (increases weight to 2lbs)
Z series - 3.0lbs, 13.1" 1600x900 or 1920x1080, 7 hours battery, dual-core i5 2.4, 2.53 or 2.66GHz or dual-core i7 CPU at 2.80Ghz, 4GB, 6GB or 8GB RAM, RAID SSD (2x 64, 128 or 256GB drives)

The P and X are both netbooks, whereas the Z series is a true notebook with DVD or blu-ray drive.

The P series is definitely the lightest netbook on the market.

and one of the most expensive too. IMO the price does not justify the specs.

Yeah, but I was looking for something similar to the old TZ series. True biz-powered ultra-lights. I guess those aren't made anymore.

Nope, although pretty much Sony has the only one who ever broke below the 12" barrier with any regularity for the US market for some years now (there have been some very nice Toshiba Librettos not imported, and some very small Fujitsu UMPC/tablet models, a few of which have made it over.)

In terms of CPU power, some of the CULV netbook+ models have been pretty comparable, but they're not generally quite as light as the TZs were and I'm not aware of any in a 10" screen (lots of 11.6, a handful of 12.1). The 10" dual core (Atom N550-based) netbooks are the closest you're going to get but you're sort of marginal in power.

The X201 and to a lesser extent the m11x and TimelineX 1830T are much more powerful, and it would be interesting to see if a company more concerned with minimizing the size decides to take the i5-ULV processors in the latter on. The X201 (and the similar 3lb/12.1 models from Fujitsu and HP) is probably as small as you can get and actually use the non-ULV i5s.

6 cell battery - I don't have any power saving tricks turned on, so I'm sure I could tweak some more life out of it if I needed to.

Thanks!

I have the X201 with the 6 cells and between 5-6 hours is what I am getting too.

Thanks for the additional data point. It sounds like these are probably the best deal out there in a small business notebook.