I agree except for disparaging the AVP as not being a real computer while the steam frame is.

One lets you one-tap download native Microsoft Office, one runs it through a browser or via bespoke vm/wine configuration.

Instead, I'd say the difference is that both are consumer devices, AVP geared primarily toward computing while steam frame is geared primarily toward gaming, but the steam frame is open enough for you to develop upon and customize to meet whatever use case you desire.