Nobody has a crystal ball.

If you think Bitcoin will have significant price increase soon and will stay up for the majority of the year, buy a mining share.
If you think bitcoin will stay somewhat low in the mid tern, trading shares make more sense. 

You can do both by buying trading shares now and if bitcoin goes back up you can buy into the mining pool.  You'll miss a week or so of returns but it if stays up you still win. 

I can't advise you on what Bitcoin will do, but I personally haven't bought a mining share since January.