Ruin how? They're farm implements. If you're trimming a couple thousand feet of hedge along a pasture, you're not really worried so much about the aesthetics of the hedge.
You wouldn't use one in your back yard.
Thanks Carson, sorry about delay in getting back. Signal was down.
Yes, they are good farm tools and for the sort of hedge you are describing, they are the only way to go.
I have to cut a mixture of hedging which includes Laurel, Wild Rose, Hawthorn, Prunus (sloe), some sort of Yew, some poorly linked elm (some with the beetle already thriving) and Beech. In some places the aesthetics do matter. For some stretches tractor and flail access is possible. The Elm is not too important as it dies back every 12 years anyway.
Shaping with a flail is pretty good but I have heard that it is bad for wildlife and should not be done annually?
Looking at the cut ends, the flailed sections are sort of 'mashed' rather than cleanly cut as you would do with a power Stihl or Husqui, say, or hand pruner. I wonder if this allows for disease entry and excessive transpiration?
Hawthorn bounces back from any abuse. Any ideas about laurel and the others?