every 5 or 10BTC ... use a new wallet.
i do this.
when you pay ... seller don't know if you have more than 5 or 10 BTC.
Although this is an old answer, it's still applicable and with new bitcoin wallets with new innovation coming up, I think users will have a wide array of choices where he can store that 100 bitcoin 5 bitcoin for every wallet is still a good option but can the user remember every one of it?