Such discussions always make me smile, discussions will never find an end when there are obviously big differences in knowledge about the discussion theme, like shaders and so on.

Shaders are not an engine. They are little programs running on the 3D card and their speed only depends on your 3D card when the code is similar.

I have tried Unity shaders with the pro trial version and found, A7 kicks Unity's ass into orbit shader-wise. Not because A7 shaders are faster, they are exactly as fast as Unity, but they are better to write. You see the effect immediately while you write the code. Unity can not do that. And for any decent shader effect you must pay 5 times the money that you pay for A7.