Is there any significant difference between Samum and Zerrikanian Sun?

[Fatmagic]

One says it stuns, the other says it causes blindness, but both seem to achieve the same overall effect of crowd control - in addition to modest damage - and Zerrikanian Sun is much easier to craft with its more readily available ingredients (Vitriol is common as dirt, Aether not so much).

Is Zerrikanian Sun just a more efficient Samum, or is there something that makes Samum stand out from Zerrikanian Sun and still make it worth using when you have ZS?

[Fatmagic]

Also, does the Wolf potion's boost to critical effect also apply to Bombs? I know it applies to Igni and Aard, how about Bomb effects such as the poisoning chance of Devil's Puffball?