Antpool.....
Why on earth would the farm that produces the most empty blocks care about block size? Empty blocks are empty blocks, no matter what size they are. Not only that, but they provide absolutely zero customer support to anyone daft enough to mine there. Their code is shoddy, buggy & unreliable - just look at their so-called "support" thread - it's abysmal.
They don't care about Bitcoin, it's users or the network as a whole - all they care about is ripping off for profit & taking control of the Bitcoin network.