Conclusion: Just perfect!
On the housing there is no reason for criticism. On The Contrary. It is the perfect companion for the IXUS (220HS). All buttons incl. Zoom can be
operate very well without restrictions. It is completely sealed (tested up to 3m depth) and also not fog up.
And the best part: It has virtually no loss in quality (at least not visible to the normal user) to the housing. Straight on the beach is the perfect protection against sand, etc. Even the lightning kept its role perfectly.
So after some initial skepticism by the reviews here, I must clearly give the all clear and can recommend this product without restrictions.
Conclusion: Great pictures both above and below water. Impeccable service. Cheap Price.