Fact is with me, regardless which number on paper you preferred.Eh, wrong,the figure which was quoted back then was that the power cover would increase the battery life of the Surface Pro about 75 %. Seriously, did you even read my post? The battery in the Surface 2 is 30 Wh, which is the same size as the battery in the power cover which is also 30 Wh, hence it will obviously approximately double the battery life as it would do and does for every other tablet around. The Power keyboard cover battery for the Lumia 2520 is only 50 % of the size of the tablets battery, hence it will give a lesser boost compared to the Surface power cover. You are just spreading misinformation here.
And I said, whats left is the user report back. And the one besides me is telling me exactly the same like most review do.