I have knee length hair, DD (4) has hair just past her waist and growing.
99% of the time, we have matching single plaits down our backs. I've had comments about it being 'cute' that we have matching hair, but, actually, it's only matching because it's the best balance of comfy, tidy and quick to do there is!
A ponytail takes time to put in tidily - i.e. central and with no bumps of hair - the bobble has to be tight for it to be effective, which is bad for the hair strands, esp. everyday, and it does nothing to prevent tangles and contact with other heads.
If I send DD to preschool (and school, in Sept) in a ponytail, the bobble falls out, she gets food/paint/glue/snot etc in the length, it gets full of tangles and we're most definitely risking nits!
Instead, it gets plaited and covered in Vosene tea-tree spray. The result - a child who doesn't spend all day messing with her hair and who (touch-wood) has gone a year with no head-lice, depsite them going round.
If you're really looking to have a no-fuss, practical hair style, learn to plait!