As you know, we carry Precision Magic's Magnetic Scotch & Soda. We've not had any complaints from our customers about it. What I will say is that I've heard a lot of differing opinions from people, but no complaints.
With any magic, I suggest that people consider how they'll use the item before they purchase it.
I've had a customer that was looking for a trick to fool "the boys" at his weekly poker party and for him this was a big hit. The magnetic feature made it easy for him to use and he didn't want to have to worry about losing the bang ring from a regular set.
Conversely, I sold one to a working restaurant performer that said he liked it as it was easy to instantly reset as he goes table to table.
Hope this was the kind of feedback you were looking for.
Good audience management can help a performer get around the varying levels of scrutiny that props can withstand.
The Trick Shop - Temecula, CA