I’ve had three 29ers and I’m never going back. Pretty much everything I ride is rooty, muddy, loose, tight and twisty woody singletrack and none have them are slow through this stuff. If you’re chasing someone on a 26er it feels like you’re cheating.
If you want to try one try and demo it for a few days, you need to adjust your riding style to get the best out of them otherwise they can seem a bit sluggish and less manoeuvrable.