Hello \:\)

I am looking to buy a digital piano as a replacement for a real piano for my studentroom.

I've tried out the Roland RD150 and I really liked it, sounded most like a real piano to me.
Now I've seen a good deal for a Roland RD170.
I've read on the internet that the RD150 isn't manufactured anymore and was replaced by the RD170, so I assume both models are similar.
If the pianosound on the RD170 is virtually the same as for the RD150 I want to go buy the RD170, I don't have an opportunity to test the RD170 myself however unfortunately \:\(

Can anyone tell me the differences between the Roland RD150 and RD170?

Thank you in advance,