They just had a forum by the various manufacturers, and their consensus was that with the modern tank insulation, stand by losses are minimal.
Licensed residential and commercial plumber
Energy Star requirements of today's appliances mean it's harder and harder to justify the expense of adding on a supposed energy saving device when reflected off the reliability. Spend the money on insulating the pipes, sealing leaks, and maybe finding a decent water-saving fixture. Money better spent, IMHO.
Important note - I'm not a pro
Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013