I've looked at the reviews for some of the Palit cards and they don't seem to be the best. The zotac ones are ok. Apparently the ROG cards are better with cooling and are better for overclocking. What would you guys advise?
I'd personally say it's not worth it, they both offer very similar performance and it's essentially just paying for the brand I'm not knowledgeable on the overclocking part but they should all perform kind of the same in terms of cooling and performance! For the price difference I wouldn't say it's worth it
The cooler is potentially better on the ASUS model vs the reference design, but for any real overclocking potential you'll potentially be water cooling (you can probably find information about this by googling the ASUS card reviews).
Overclocking a GPU (as far as I am aware) is still not covered under normal warranties (PCS nor most suppliers) so this should be considered if you choose to overclock your GPU.
That said, I'd agree with @TomBerry in that unless you're really wanting to overclock the card there's probably no reason (outside aesthetics?) to spend the additional money.
Cooling is possibly better with the ROG Strix due to it's Tri-fan design (as opposed to the dual-fan on the Pallit...not sure how many on the Zotac) but, as Steaky says, overclocking that chip would necessitate water cooling to be sure of stable temperatures. Personally, I'd be happy to go with one of the other cards and save the £200 difference but I'm not an OC'er and only have personal experience with the Pallit 2060S which obviously has much less thermal output