Is it as big as Bitcoin ?
not even close!
Should we buy some tokens ?
right now, no because it was recently pumped and now the price is in a bubble which means it will only go down from here with some small come backs (dead cat bounces). and you can see it already going down hard because it is getting dumped these days.
generally again no. because it is a manipulated coin, and the coin itself is centralized unlike general altcoins.
Looks like Ethereum can be mined as well.. what is the profitability like, has to be better than Bitcoin at this point, plus good to reuse all those miners hardware ?
mining ethereum was very profitable at first but i think it is nearing the end since the difficulty is higher now and price is not really as high as before.
and when it comes to mining you have to consider the electricity cost too.