Yes, but it depends what set.
In my opinion, no electric anything would replace a real acoustic.
It's like me with my piano. I would never ever ever replace my acoustic stand up piano for anything and I have a digital up stairs.
There is no comparison to the sound/playability.
To be honest, the only ones that stand up to an acoustic are the Roland V series of digital instruments.
Check out the more expensive Roland V drums for example. They are pretty damn realistic, but expensive:
Like the TD-20KX
YouTube - Roland TD-20KX VDrums - Nevada Music UK
There are sets near the quality of this, that range in prices that you'll be able to check out on Youtube no doubt as well, and might be more affordable for you.
But DO NOT pick up a cheap plastic looking set, that can't be customized for example, and only has a certain range of velocity sensitivity. ESPECIALLY for a drum set. You just won't get the playability you want.
For a digital piano, I think the best you can get is the Roland V Piano, which doesn't actually use samples at all, but instead, uses a processor to create all the sounds in real time.
