Are the spell feats like metamagic worth it?

[Puppet Master]

I never get them, my spell casters are around lvl 7 and I usually have them get the feat that adds +1 to saving throw for spells, spell penetration, or toughness

[wendigo211]

They can be. Part of it is spell slot utilization, e.g. using Hieghten spell to memorize a third level spell in a 4th level slot. Some of it item availability, e.g. I generally cast more extended spells than I have rods for, so I find that one useful. You can also use it to stack metamagic. E.g. Empower a spell and then cast it with a Maximize rod to get both effects on the spell.

It's a bit better for vancian casters (Wizards, Clerics) than spontaneous casters (Sorcerers, Bards). Spontaneous casters take a full round to cast a spell with metamagic.