Just wondering for ideas for something that meets my needs.

Requirements:

* Must be lightweight - e.g my existing tablet is only 540g + keyboard.

* Must have 4G data support (I think this rules out ASUS tablets).

* Must have (standard) keyboard (e.g. with escape and backspace keys in standard locations) that is usable on train without tables (I think this rules out most other tablets).

* Don't particularly care about OS, although I note that applications I use (e.g. ssh clients) don't appear to be particularly great on Android. Willing to try ChromeOS.

* If ChromeOS or Android based, should support installing 3rd party OS or at the minimum have regular updates (rules out Samsung Android).

Optional extras:

* Good battery life (possibly conflicts with being lightweight).

So far, a Google search suggests that the HP Chromebook 11 ticks a lot of these boxes (e.g. according to one review is the lightest Chromebook available - not sure if this is still current information), although it is missing some desirable features for a Chromebook (e.g. no touch screen, no standard HDMI socket, and only 2GB ram) and is considered by at least one review to be "Frustratingly slow".

Any other suggestions?

Thanks