Yep. And I have (only once, as normally I invest some time and effort into voting).
However, technically now you are supposed to attempt to put in a valid vote. I'd prefer if it was mandatory to show up, but they said to people 'Hey, so if you don't want to put in a vote, just rock the abstain box...or just put in a blank slip.'
But you won't hear that message, because technically you're not supposed to. If course it's secret ballot, so there's no way to stop it...but candidates want their name first on the ballot for a reason.
It's not a massive impact (although I've heard it estimated at upto 2%, although that seems unjustified) but it is an effect, especially on a seat by seat basis (as the impact will depend on preference order, to a degree).