I guess what im getting at is ... should I sell altcoins when they reach a decent high (take profit or reinvest in BTC) or HODL with them with the hope that one day they might explode like BTC ?
You need to decide how much profit you expect and when you will sell. However, you should not expect too much profit in altcoins, if you expect too much profit you may face losses. Because altcoins are risky, altcoins will not be profitable in the long run, and it will be difficult to recover if you suffer a loss. So be careful, don't delay to cash profit.
selling when you have reached the target is the best decision. not only on altcoin but also on Bitcoin. however, Bitcoin may have a better chance of recovery in the future if there is a decline.
Some people may set targets that are too high for the assets they own, or some buy and hold them without a detailed target price to achieve.
it is better to make a small profit from altcoins in the short term and sustainably than to be trapped in altcoins that never recover.