I don't have believe in othe cryptocurrencies other than  bitcoin becuse bitcoin doesn't have any centralized agencies and other currencies have some sorts of control of other people directly or indirectly so i belive only in bitcoin and i would love to use only bitcoin.
edited : Secondly we are seeing that many new altcoins are coming in the Bitcoin network and also many of going per month , so I think it is more better to convert your Bitcoin in Fiat than in any other altcoins .
Here we have more trust in Fiat after Bitcoin because Fiat usually don't get crash from its initial value .
So we have more better option than the cryptocurrency .