The z3 does look great and it's the size I am looking for. I noticed Argos are selling it for £199.

I got an asus z300m 10 inch tablet 16gb internal storage with an sd card slot, marshmallow out of the box, dual band wifi and dts sound from a front facing speaker

The only negative is its the screen resolution 1200x800 720p

£149.99 from currys

Nvidia has just cancelled the follow-up tablet, so I wouldn't be buying a new Nvidia shield at this stage, as god knows how long support/updates will be available.

OP: There's a rumoured Nexus 7 coming out later this year (maybe as soon as next month), so might be worth waiting for a bit.

(ETA: seeing thread is 6 months old, OP has already waited LOL).

That's ok, such a lack of new tablets he is still probably waiting.