Summoners and Superior Summoning

[Karrothesus]

If I have my Eidolin out, and have the 3rd level feat Superior Summoning, as an Unchained Summoner, can I then summon another creature using the summon 1 or 2 spell? Or is an Eidolin special so that you may never summon another creature with your Eidolin active?

[Edward McGee]

You may cast summon spells (As a full round cast) while your Eidolin is out. You just can't use your class ability to summon.
You must still have the summon monster spell as one of your known spell's to do so.
And Superior Summoning let's you summon additional monsters when casting to summon lower level monsters.

An alternate option is to use your class ability to summon when you don't have your eidilon out then spend a full round casting Summon Eidolon.
That way you use just one known spell slot instead of taking up multiple slots with summon spells.