Once the spring is damaged, it is almost impossible and impractical to try and straighten out the spring. I currently throw with a set of 24 gram Meteorite darts that have been converted to use hammer head points. I did notice a huge increase in the number of bounce outs. It seems that the springiness of the shaft counteracted and neutralized the actions of the hammer head points. I tried these shafts with fixed point darts and did not notice an increase in bounce outs.
Tighter groups are possible and do occur.
Feels like a normal shaft when throwing. Durability of these shafts is very questionable. After destroying 2 shafts in 5 minutes and a third within another 20 minutes, the cost of replacing these shafts can be quite expensive. Robin Hooding one of these shafts is a nightmare. Obviously, the Robin Hooded shaft will bend, thanks to gravity.