I have a handheld, and borrow a non-handheld if i have to.

The handheld is one of the variants you find if you search amazon for "handheld steam cleaner". There are a few real companies there (dupray, etc), and the rest is everyone selling the same mass-produced models.

I have one of those :)

If you are trying to steam clean cement grout, then using something larger because it will take a bunch of steam pressure to clean it.

For a non-cement grout, it's usually just stuff stuck on top, so it takes a lot less steam to get anywhere. Just enough heat + pressure to unstick it. Which is easy for a handheld.