When I needed a mallet, I was cautious of purchasing one that is Silverline branded, but so far it hasn't disappointed me.
The head has stayed on the hammer, although I have not used it much - I don't often require a mallet. It hasn't marked any of the wood I've been knocking with it, but I haven't brushed the hammer head against it. I suspect that if you brush the hammer head against some wood, it will likely mark the material.
I've no reason so far to give it anything less than 5 stars, but if the head should fly off like I've been expecting, I'll certainly amend my review.
This review is also available at Amazon: https://www.amazon.co.uk/review/R2ZCQ1XKK9J27W/ref=cm_cr_rdp_perm.