It depends on how you see the future of Bitcoins and Steem in short term and long term, lets say in 1 year and 10, and what's your plans!

While Bitcoin can be considered "safer" , steem can be riskier but can also give you much higher returns, but again both bitcoin and steem are risk and can crash, no one knows.

You gotta be well informed and somehow up to date with what's going on, competition, adaptability, and the bigger picture of what's going on.

You always have the option to be flexible, one month invest 50% in bitcoin, one month 50% on other 5 coins.
Keep in mind that there will always be the new thing that's worth investing into.