A question for experienced summoners

[Rudolph]

What you write make sense, Deathgrowl, and probably goes for most Druid builds. Take a look at this particular one, though. It is build around the new shapeshift spell (which doesn't allow for spellcasting at all after shifting). This means pretty much all the spell slots can be used for buffs, ideally mid to long-term. I was trying to make something very different from the usual Druid but still comparably powerful in its particular way.

[Rudolph]

Fighter 5 is not the best option. One more level of druid still ends at 5 apr while preserving caster level.

Fighter 5 gains a BAB point over Druid 13. Since the build has 31 CL already, and AB is at the low end, I think that is better.

[Deathgrowl]

I see. Well, in that case thaumaturge with summon creature IX is probably better than the druid companion... I have no idea what spells from the druid list work on those creatures though.