What's the "Summon Familiar" ability worth?

[Crothian]

Familiars, like most things, are very good for those who know how to use them. But many people think it's to much to keep track of or their DM will kill the Familiar if they make the slightewst mistake with him.

One feat is perfect because later in their live the wizard can spend a feat to aquire a familiar. This way it all balances out.