Super easy to install.  Easy to cut with a razor or sharp knife.  Put these up in an afternoon.  They flex well around my old plaster ceilings many imperfections.  The down sides are that the tiles can easily be scratched, particularly with fingernails while pressing into position.  They look much better painted.  I would give a higher rating, but the cost can barely be justified.  These are polystyrene, like the stuff used to package food for pennies.  The tiles must cost almost nothing to make, so I cant understand the cost.  Convenience can only justify so much.