I took apart a LA motor that had one of these, The chain wore completely threw it and the chain was digging into the metal. Don't know what the life span is on them but after i seen this i stay away from them. If somebody made one with a roller it would be a better design.

 

When I installed my tensioner, I made sure that the oil slinger was in-place on the crank and that one of the bolts that bolts the tensioner to the front of the motor had a hole drilled through it to provide plenty of oil for the chain area. No issues here to-date, however, my truck isn't a daily driver..