I don't like the flareless look since it's just so base model looking but the painted flares take on too much abuse off road and start to look crappy with the scratches real quick but I think the flat black plastic flares are a nice compromise right between.
The plastic flares also do protect the fender edge also so unpainted plastic is the best combo for those who do off road IMO.
I specifically bought a '99 since it's the only Highlander/Sport model year that had the skinny flares since it's the widebody painted version after that.