[clug] Chasing a Cheap Android Tablet

[jm]

Been eying off tablets for a while but can't really justify the price of 
the high end big brand models. Poking around the Internet it seems that 
there is an emerging number of cheap models out there. As my 
requirements are rather relaxed beyond a few key features I should be 
able to find a suitable unit. So far I've found plethora  of models but 
am having trouble separating the wheat from the chaff.  If any one would 
care to venture their opinion or experiences here's my rough list of 
requirements,


* USB on the go
* Wifi  preferably full a/b/n
* Don't need 3G
* Approximately a 10 inch display
* Capacitive screen with multi-touch
* Good display quality (resolution, viewing angle, contrast, etc)
* Android 4.x
* Future O/S updates for at least a couple of years
* Built in speakers
* Headphone connector (3.5mm stereo)
* Microphone
* Microphone plug would be a nice to have but not necessary
* Large battery capacity 8+ hours of running time
* Decent CPU as I may wish to run Octave and a few other apps that take 
as much CPU as you can give them.
* 8GB or more of flash storage
* SD or other removable storage would be nice
* Reasonably durable (which may include the use of a leather case)


The question I have the most difficulty answering is which manufactures 
have a history of providing ongoing support including O/S upgrades? 
Which models are most open?

Now over to you guys...

Jeff.