For me both bitcoin and altcoin are good... As of now bitcoin is very popular and has a lots of potential in market while altcoin is good also because it has a potential also to rise in the market. So i think it is better if you have this both in case the bitcoin has a low value in the market. You can used your altcoin but make sure it has a good price.  It will not harm if you keep both of it in your wallet.  It will depend only to you on how you execute your greatest strategy in the market.