Yes. I bought the same lens sans hood and was shocked at the rip off price for the Pentax official version. I tried both the standard generic petal hard plastic and flexible rubber hood. I found both hoods will vignette once you open up to about 20-22mm. The rubber hood i can fold back a notch for 16mm shots (if i remember, since the viewfinder is not 100% I don't notice during composition). The wide angle hood seems worthless in terms of protecting the lens from unwanted light so I dont use that one. Bought both generic hoods for around $8 each as I recall and get some use out of each but if I had to settle on one it would be the rubber one. Just remember to fold it back part way when shooting at 16-20mm. There are a zillion hong kong ebay sites that sell these. One state side place i have dealt with a bunch of times and can recommend is
The Camera Hunter about all he carries are those kind of replacement accessories. One man shop so feel free to ask for stuff you dont see listed and he can usually get it or at least give you a personal answer.
edit - just looked up the flexible hood at
www.thecamerahunter.net and its on sale for $5.19 + usps from WA
Lee
That said, if I ever run across an original Pentax hood for $15 I will own it too.