I already reported repeater issues, it was marked as "resolved" but it still not solved and I reported it one or two months ago.
Now I found new issues with pistons: they dont drop the block (I mean let the block) when moves fast. ; Pistons cut redstone dust passing in diagonal throug repeater ; To place a piston vertically, you will need to RIGHT down the block wich you want to place, wich is VERY uncomfortable.