A Pringles can works perfectly as a Cantenna. You need a larger dish such as a Primestar elliptical to give it proper full illumination. I used one for 5 years, 300ft + through a woods, and worked fine 95% of the time.
Or, you can build a Biquad feed, and it mounts perfectly on a 20" Dish antenna inverted to point better for that type of service. My testing at my location actually showed that a properly built Biquad worked better, (and is more stealth) but a Cantenna has a "tighter" beam.
http://www.engadget.com/2005/11/15/how-to-build-a-wifi-biquad-dish-antenna/
If you were comparing the Biquad to a pringles cantenna, then yes, I'd expect the Biquad to outperform. The pringles can is considered, by nearly every source I could find, far too small in diameter. Also, the length is not ideal. I was trying to find a very long, very smooth can, but ... It's impossible to even special order those things. Instead, I'm probably going to go with a length of aluminum duct work. It's very smooth, very long, has a good diameter at 3", is readily available, cheap, workable, and resists corrosion. The only downsides I could see is 1) the locking ridge which runs the length of the can and 2) how to 'end' the can... I'll probably cut a circle of aluminum and use some JB Weld to seal it on the end. It may not be perfectly microwave tight, but I figure it's close enough, and better than a ridged can bottom.
I'm not so sure the beamwidth is all that large. It's coming out of a cantenna remember. That's one of the reasons I chose a cantenna as a feed rather than the biquad - I'd like the tightest beamwidth possible. I figure it would pick up (and cause) less interference that way. My cantenna is going to be about 24" long, so that should give a real nice tight beam. At least, in my own little mind.