Regarding the Fullcover Block from Alphacool.
This thing is trash, do not buy it. It costs much the same as EK's block but has dire quality control. I am getting temps that are barely any better than the stock cooler. Can't overclock more as the junction temp hits 110 easily.
To make things worse they can't even make a backplate properly. This is how the backplate fits (holes are lined up correctly with the PCB):
Looks like whoever machined this put the wrong numbers in as everything is offset by 1cm. Even if the holes were machined correctly, a standoff was fitted wrongly and broken, was like this in the sealed bag but they sell it anyway! Zero QC from what I can tell. I removed the LED strip from mine as this is known defective and can destroy cards.
Suffice to say that Alphacool are running a cut price operation and it's clear that they were trying to rush these blocks out. They even failed at that as mine was delayed for two weeks and EK released theirs sooner without problems.
The cause of poor temps is likely poor design combined with rough machining. The actual machining marks are very visible over where the die makes contact so I might be able to improve things by sanding it down.
I would recommend buying the EK block from OCuk now that it's available. I very much regret being impatient and buying this. Especially considering that I only just found time to fit it, I should have just bought from OCuk when I wasn't busy.