I wonder if BitCoin is going to end up being used for saving (like a gold 2.0 as @colombiana said) , while other faster/cheaper cryptocoins are used as currency in stores, online, etc.

If you think about it, we no longer use gold to buy things because paper is a lighter, cheaper, and more convenient technology. That doesn't mean that gold has lost its value. Similarly, I think BitCoin can retain its value even if it's no longer optimal to use it for day to day purchases.