Indeed. I wonder if the push-button ones comply with the Part M building regs? The TGD notes;
(u) the activation of a manual flush mechanism should be clearly visible, easy to use and require little strength and no fine hand movements. TGD G should be referred to for guidance on efficient use of water for flushing. Spatula shaped WC flush handles are suitable for people with a wide range of abilities and can be activated with an elbow or fist;
From http://www.environ.ie/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLoad,24773,en.pdf