Nothing is the same, it's true, but for serious practise a digital can be better. The key response and weighting will be consistent (good luck getting that with an old instrument) and the tuning spot on.
I used to be a sceptic, but playing the latest digitals which acoustically model the soundboard, strings and action of a piano, the experience is very impressive. It genuinely does feel like playing the real thing, even if the sound comes through speakers. If I come to buy my own piano, I'd go digital.