I've never done a taste test and the beer you mention is not on my radar (I don't like stout). Have never seen a sierra in a can, I'd try it and compare it though. But my personal guess would be that it's cheaper to fill it in cans than bottles, no? I used to love Sierra Nevada, was my favorite for many years, but I drifted away from it. Either they changed the recipe or my taste changed. Favorite right now is Kona Brewing Longboard Island Lager, and some red ales. And Schneider Weisse and Erdinger Weissbier, which are my absolute favorites, but they are too expensive here. Part of it for me is probably also that I am Bavarian and the only beer you ever could find in a can (and you had to search) was the cheapest swill you can find. So it might as well be a inborn perception
That aside, I simply don't like cans, not for beer, not for soda. They taste and feel metallic to me. Now, I never pour my beer into a glass (I guess an abomination all to itself, LOL) and a beer in a can gets warm much faster (or seems to at least) than one in a nice cold bottle.
The brown bottles prevent light quite well and beer never lasts long enough around here to oxidize or go bad. I used to hate the little 0.33 l bottles here in the US, but now actually prefer them over the German 0.5 l, less beer getting warm and flat.
I noticed Sierra went away from the screw top caps for freshness (they say) which makes sense, they never seemed to be attached all that tight. But I'd balk at Sierra in cans. By the way, where is that info from? I just checked their website and it only shows beautiful frosty bottles.
Beer in cans just has that PBR homeless guy kind of touch to it (IMO). I am always excited to get a glass bottle of a nice Pilsner on Lufthansa flights, instead of the Heineken stuff in a can.
As I said, personal opinion, I can't even remember the last time I bought a beer in a can. I did find a forgotten case of PBR in a safeway cart a while ago, free beer! And I did buy the Guiness with that little fuzz maker inside when it came out, seemed pretty ok, but I'm not a fan of that beer. Unless everybody fills into cans I'll stick with bottles :-)
And I won't buy wine in tetrabricks, I don't even like screw caps on wine bottles, I like the cork opening ceremony.