definitely.

And honestly... Banks in the real world are far more cheapskates when coming to interest on account balance.
if you find one that gives you 25% yearly on savings.... and accepts deposits from around the world, from normal persons, and not from tax-paradise based companies, please give the contact 

for the time being, coinlenders is the best choice in my opinion, for keeping a large part

and keeping btc offline... well, is kind of hiding them under the mattress  xD! (though I recognize that having a bit available in a machine/hdd that would be seldomly used... like some sort of a physical safe... unless the drive sounds TAC,TAC TAC!, is pretty safe as a storage