Force Sword vs Instant Weapon (Comparing as Magus)

[Fox Soul]

My character is a Magus, and I am currently comparing Force Sword with Instant Weapon.

From what I understand the only significant difference between these level two spells are:

Force Sword
-Has +X enchantment, representing its a magic weapon
-Can be given to others
-CL 13 version cannot be attacked or harmed physically

Instant Weapon
-Weapon is considered Masterwork, meaning it's not a magic weapon
-Can be made into any weapon
-Has more Hardiness

Force Sword appears to be better if you just want a sword, while Instant Weapon appears to be more versatile as it can be made into any weapon.
May I please have your input which you think is better?

[Zwordsman]

Considering you are a magus. I.e spell combat and or spell strike.
it seems like force sword is probably a better sell.
Sure instant weapon can be any weapon..but if your spell combating your weapon choices are a bit limited and in those limited choices there really are a few specific ones..

Granted I haven't read each spell lately.

[avr]

Actually force sword gets the undamagable bit from the start, it's just the enhancement bonus which scales with level.

The big difference besides that enhancement bonus is that force sword worries about enemy SR, instant weapon doesn't. Instant weapon is thus more reliable & would be the one I would go with.

[Bladelock]

Also instant weapon gives proficiency which is great for exotic weapons. Need to spell strike with a little reach, create a whip. Want to make someone flat footed with trip rather than making them prone, make a seven branched sword. What ever you need, you got it and you know how to use it.

[Louise Bishop]

Don't forget about force sword:
Can damage incorporeal critters..cause you know force.
And you can hook Toppling Spell Meta magic. 3k gold for a rod of it. Let the hilarious times begin.