I agree with Brian, because I very seldom backpack in national parks. If I do, it's in Olympic National Park which rents canisters (including some Bear Vaults) very reasonably ($3 last time I looked) and, most important, has outside bins to return them after hours.

I regularly use the Ursack (and I now have the S29) because I can't throw (hurts shoulder joints) and never could hit the side of a barn even when inside it! I've never had anything get into even my old ones, although I found evidence that birds and mice tried!

I did buy a Bearikade back when we were visiting the Olympic NP beach every year (and before I found out it wasn't on the IGBC list). I have used it only twice and will probably end up selling it.

BTW, REI now carries the Ursack S29. I got mine last fall. With their 20% off coupon and free shipping, it's cheaper than getting it directly from Ursack.

So what you buy really depends on where you regularly backpack and your individual quirks and desires. But, as I've stressed here, always check the specific rules for your destination!

Just remember that bears (strongly motivated by food) learn faster than most people, so what works now may change in a year or two!