Nightjet Amsterdam - Innsbruck, is it that bad?

I've been looking into booking the nightjet from Amsterdam to Innsbruck and back in February once the tickets start selling.

Although I'm reconsidering my options now that I've seen quite some people saying there's many instances of sleepers getting replaced by couchettes, and couchettes to seating carriages. It's for a ski trip, so delays are tolerated if it's no more than 3 hours, but it would really suck if we have to end up sitting on seats the whole night.

Is there a way I can find statistics about issues on this nightjet and others, regarding delays and downgrades in the carriages used?