I use the Flex 2 days since the slots in concrete / hollow brick and concrete screed (currently build our house in order), I have to say, handling just great, not too heavy, not unbalance the gear that would go to the wrist or the like.
At first I was skeptical of the price, but absolutely wrong! Can I only know each!
Sparks switch - on / off. wonderful with me, I do not know what other users have problems with it ...
Conclusion: For hobby and handyman absolutely perfect!