From what I know of the timers I checked out before my current system, is that the digital timers in the same price range as the analogue support lower currents.
The analogue just gives you the option to set the on or of state generally by 15 or 30 minutes, and digital timers have entire ranges, programs and what not to be able to switch on or off down to a minute combined with days/weekends.
One could argue the mechanical contruction of an analogue being more prone to damage or wear and tear, but the digital gets it flaws when the memory battery fails or corrosion gets the better of the print.
I eventually went with an analogue for the lights, and a digital for the ventilation.
Obviously the digital one wasnt up to par for a grow (the ventilation), so I replaced it all with a computer controlling a set of relais.