why not both? it can avoid big lose if you do both mate. make sure that you buy bitcoin more than ICO
bitcoin is good for holding, but it can give you good profit such as ICO
in any case, if you are sure of any project, then the investment in ico company is always attractive enough, especially if you consider bonuses.
the funds you have 100%, 50% investment in ico, and 50% more investment in bitcoin,
maybe that's my best advice