One of my used engines had one when I got it.
The previous owner had nothing bad to say about it.
Looking at it's construction, it seems well thought out and durable.
The only thing I did not like about it is the pawl drum (I made that name up)was held on to the end of the magneto shaft by friction alone. If the nut were to come a bit loose the drum could spin on the end of the shaft instead of turning the engine over. I may decide to use it in the future. If I do I will drill a hole through the drum and into the magneto rotor. Tap threads into the magneto rotor only. Then use a small bolt or screw to re-inforce the connection and positively stop the drum from ever spinning incorrectly.