Normal chain will (no "O" ring) will get worn between the side plates every time the chain goes around the Sprockets, as there will be friction between the plates. "O" or "X" ring chain provides a cushion between the plates and also retains lubrication between them. You may save a few £/$/Euro or whatever on purchase price but will use more than that on lubricants. Not worth the initial saving. Buy the best chain that you can afford for no other reason than lack of hassle with maintenance. Also, change your sprockets at the same time, worn sprox will kill a new chain in no time at all.
Seasons Greetings to you and your`s, which ever God you may worship.
Let`s stop the fighting and all buy Bikes.
Rob Chamberlain & Family.