I usually find that sites that implement it place form above functionality. Sure, they look nice, but it's usually much more difficult to find information. If you intend for that page to be an art exhibit that's one thing, otherwise you may want to reconsider forcing your users to scroll endlessly to gather tiny breadcrumbs of text.
I'd say parallax scrolling has become really cliche nowadays. I still have it my website along with a blurring effect that can be seen on webkit browsers.<p>If you want to check it out: <a href="http://raphaelcruzeiro.eu" rel="nofollow">http://raphaelcruzeiro.eu</a> (source code is on github). This was implemented 2 years ago I think, and it's not something that I would do again for a new website.<p>A few points I'd like to make:<p>- Tough the blurring looks cool it can really bog down the browser on a slower machine.<p>- There's no way to make the parallax work seamlessly on iOS devices (the js engine stops while scrolling). The only way to do it would be to disable real scrolling and use a pseudo-scroller which, IMHO, always sucks.
Annoying when it's implemented in JS and bogs down my browser. Annoying when it hijacks the scrollbar. Don't give a crap either way if it does neither of the above.
It's one of the nicest features that you can add to a simple front end site, like a portfolio for example. Even better if you write it yourself for the above scenario!