I've used dozens of these Bosch R2 bits with my impact drivers and they work fine. They seem to last a bit longer than the less expensive alternatives, but I haven't actually tested this hunch empirically. The problem with bits is that the square corners begin to round because of non perpendicular alignment with the fastener - it's not that the bits shear or break from metal fatigue. My hunch is that the harder titanium coating delays this rounding process a bit longer than the bare metal.
Currently, Amazon sells these in 3-packs for $7.15 w/free shipping, which is not much more than the non-titanium coated Bosch CCSQ2205 Number 2 Square Recess, 2-Inch 5 Pack the sell 5 for $6.71 sh.incl. I'm not sure which is the better value as I use both. My hunch (and it's nothing more than that) is that the titanium is a bit more durable. It seems like we get a hundred screws or so out of either -- in a production environment i'm sure they would last much longer, but on the job site working on ladders and overhead it's hard to keep the bits aligned with the screws.
They work well for me. Satisfied. I recommend you get these and the Bosch CCSQ2205 5-pack and compare for yourself.