As an ex financial adviser, I would say you're kind of looking at it arse about face. (I would possibly be more polite to a client, though not necessarily).
You take a fixed rate deal if stability of monthly payment is important to you e.g. a first mortgage or you have lots of other variable incomings/outgoings. You take a variable/discount if stability isn't such a big issue and or you have a track record of financial discipline. Not talking about credit rating here, more about how much of a muppet you are/n't when it comes to saving, and only you know that.
Essentially fixed rates will be, on average, over the term of the deal, a little more expensive than a tracker/variable rate, but what you get in return for the extra premium is certainty and stability.
So, which will make you better off right now? Anyone who says they definitely know which will be cheaper for you is either bullshitting or downright lying. Yeah, interest rates might well go up. But when and how quickly? By how much? Nobody **** knows, and that includes the highly paid people in the financial markets who do the vox pops on the telly.
So, that helpful?