From the top...

IBM's high end is 5 years out of date.

The mid range is lacking in critical functionality when compared to HDS, EMC, 3PAR and other mid-range products.

XIV is largely a joke.

SVC is funtionally good, but too expensive for many customers.

N series (rebadged NetApp) is more expensive than the NetApp version, so why would anyone but IBM's flavour?

Flames, because someone @ IBM needs to light a fire under their storage portfolio before this market is lost to all but the most die-hard IBM shops.

Not only out of date, but never very good to begin with. Slow and unreliable. At least that is my experience and the 5 other shops that I have spoken to.