HI,
To me, Bitcoin is best for invest in Digital Currency than ethereum. Here the reasons:
* Ethereum is not just a digital currency
* Bitcoin is deflation while Ethereum is inflation
* Bitcoin is simple and limited
* Bitcoin has a first mover advantage
* Bitcoin have bigger community and Its easier to get started
* Ethereum is less known and younger
Hope you get your answer.

you are right, bitcoin is limited and that is what causes its very high price to beat the etherum is not limited. but there are other advantages of etehrum, which is the platform of bounty campaign, the way the boutny hunter get the coin / token by working and not spending capital.