If you're day trading full time and you have all the time in the world for it...and you can only choose one of those devices, which would you choose...and most importantly, why that one instead of the others?
Personally I've been choosing laptop or mobile phone because it can be used anytime and anywhere I would like to trade.
Often times, I had a convenient ways of trading and I wouldn't worry of power because we can recharge the device before bringing it from somewhere else.
Even at work I can still trade and monitor my asset as long as there's safe place to do it.