I tend to not use gaffs personally on a daily basis, but more so now than before. like we all know, its about the outcome effect.
Its funny how performers - hobbyists and pros alike - tend to go in waves with the stuff. Im open more to the idea nowadays, but am careful with them because I don't want to wear out the card/coin/etc.
That's why I don't buy gaff super decks or... complex gaffs anymore. They only give you one! I like gaffs I can make myself -and are simple with a huge pay off (sanders, sankey, mayhew have gaffs like these). Panic, window, etc, supergaff decks - I would love if each product came with... 5 copies of them for the professional, or instructions to make them yourself.
I assume when you guys say gaffs - you are talking about - special cards, etc. Wax or.. a magnet or thread isn't a gaff, is it? but when you put a magnet or thread in a card - now its a gaff? By definition is a gaff something you just don't want your spectator to see? is a duplicate a gaff - for that particular trick anyway?
I've been thinking - gaffs allow the performer to do somewhat effortless sleight of hand - although we can all agree- this isn't always the case. Sometimes an effect involves a complex card construction for example - and still needs to be be controlled, changed, and false counted to really sell the idea. other times- you just have to cut it into the pack. it depends.
I used to think gaffs make your trick sleightless. When actually, if you really want to dive deep into the effect for the sake of doing so, you can discover ways to bring the gaff in and out of play with misdirection or a series of moves - instead of just leaving it in the pack, or in your hand, cardbox, etc. Not that there's anything wrong with that.
Just some thoughts.