[SpeedyChix]

At 5'6" I ride both wheel sizes and for tight and tech I much prefer the 27.5 as it's more flickable and nimble. For trails that are wide open hauling I opt for 29. Tire mass and constant re-acceleration of the larger tires can be a significant energy drain.

Your local riding terrain and trails plus preferred riding style should take more weight in deciding vs someone saying one wheel size is dead or only slacker long low geo works. If you ride terrain where there are a lot of rocks or logs ratcheting pedals or having to stop pedaling when you'd rather been the gas can get old fast.