This is a great cube-the sides turn so smoothly I haven't needed to adjust its tension at all (which is possible to do if necessary by taking the central cap off any side of the cube to reveal the screw underneath). I haven't had any problems with it (unlike with the 8x8 version of this cube whose innermost layers are still quite difficult for me to move even after adjusting its tension).
This cube is a convenient size and shape for my large hands as well, but I wouldn't use this cube for speedsolving (as its sides don't turn quickly enough for that), only for slow and meditative solving, which is how I prefer to solve this type of cube.