Bitcoin would be a good saving mechanism only if the adoption rate will be equal or more than the actual inflation rate (creation rate of coins) which is more than 10.5% a year. so choosing Bitcoin as saving method is as risky or maybe riskier than having fiat in your saving account.
Bitcoin is very young and volatile, although promising and interesting it's of course still a very risky investment. Yes, riskier than having fiat in your saving account. But with this higher risk also comes a high reward possibility though, as those who invested early have found out. And it's still early today. Good luck getting any kind of reward from the risk of having fiat in your saving account.
The current inflation rate of Bitcoin is irrelevant knowing that the maximum amount of coins there will ever be is 21 million. It's also logical that merchant adoption rate outstrips user adoption rate for the moment, but don't underestimate the cleverness of merchants to persuade the people to buy with bitcoins if this is clearly in their own interest. I think eventually adoption rate is going to very quickly catch back up to merchant adoption rate as merchants find clever ways to convince the people Bitcoin is simply the best way to pay.