Their Cordless tools are pretty awful depending on the tool itself. Certain models are prone to breakage, made of foreign parts but assembled here just so they could say "USA", cost an exorbitant amount, worst warranty they could offer.
Talon Grip and Power Edge. Terrible "modifications" to tools that worked. Few guys on here swear by them but, oh look Power Edge has been discontinued- permanently. Not sure if Talon Grip is still around.
Locking flex ratchets are a pretty moronic design as well sticking a switch out like that. The switch never likes to stay in neutral so the ratchet really cant be used as a flex only like other brands. Switch also use to be plastic.
Wobble Plus. Pull the socket out, it wobbles, go to put it on a fastener and happen to rotate so the socket is straight on, it can push and lock straight. Infuriating design that has worked fantastic as a cash grab.
Round head toothless ratchets. Priced crazy and flopped big time. I didn't see that coming.
Impact swivels. Lost the collar, got longer, in some cases substantially so. For a tight access tool this was not a good change.
MG325/725. Good power when new, huge, overpriced, terrible balance, made of...magnesium? They peel their paint like no tomorrow and are prone to locking up after some use is put on them requiring a jolt every so often. Like many products, they just had to reinvent the wheel and ultimately didn't improve anything but introduced a new set of problems.
Flank Drive + is about the only thing and that was taken from Williams when they bought them and reinvented. If it wasn't patented all of the companies would be doing it and I would not own Snap-On wrenches.
FD+ is original to Snap-On, Williams didn't have modified open ends until after being acquired by Snap-On. And the FD+ patent has since expired.
SK X-Frame, Matco 90 tooth ratcheting wrenches, Carlyle, just to name a few use a copied design with teeth and a cut-out. Wright Grip (teeth only) has been around for years as has the cut-out only (Armstrong, Matco basic combos, Gearwrench).