I got these to work up some new material without wearing my fingertips out too fast...normally use standard Martin 10's.
They really do feel "softer'(even more so than the Fender pure nickle '9's I use on electric)and have clearly been very well designed giving decent sound for such an ultra light acoustic gauge so great for long practice times.
They do take a bit of getting used to as they can bend out of tune easily if fretted any way hard.
The only serious con is that my two acoustics which normally sound very distinctive (an early '70's J45 and an 80's D25) lose some of their character and take on some of the generic,balanced but bland sound I associate with newer guitars from Taylor etc.
I don't think I'd use them long term but a very useful tool when needed.