I've tried it yesterday and indeed mSIGNA is definitely on the advanced side. Unless you've fully read BIP32 and *understands* it then you'll easily get lost as soon as you diverge form the online instructions. BIP32 is a very powerful wallet format and this application should be targeted at brokers and eCommerce developers.

For the average joe that wants more security, what I would recommend is either an hardware wallet such as the Trezor or an offline wallet using Armory (either use an old laptop with wireless disabled - ideally a fresh install - or a rasberrypi). The offline side needs very little resources.

As with any other wallet, make sure you create a backup, destroy your wallet and *restore it* before you even put any bitcoins in it, and keep the paper backup somewhere safe like a safe-deposit box.