The best thing I find with the electronic timers is that if there is a powercut or anything, when the power comes back everything returns to how it is supposed to be. No running around, pulling out cupboards and what-not to reset all the timers (and of course it allows me to have my tanks in 'sync' with each other - lol )
my most major problem to to with these electronic timers is. trying to remember how to alter the time, back and forward with the clocks. that's one thing the "mechanical" timers have, simplicity of altering the settings. just a twist of the dial.