I have the Type I Zone VI enlarger. As I understand it from Calumet, the Type I is brighter, probably because the transformers are in the control panel, versus in the head. The control panel is large and heavy, suggesting that the transformers are heavy duty.

As for small negatives on a Zone VI Type I or II, by purchasing the Zone VI Beseler adaptor (e.g. intended for the Beseler color head), it's very easy to adapt an Omega D2V condenser head to this enlarger. It's a matter of gluing a long 3/8" thick, 1/2" wide piece of rubber around the metal housing for the condenser so that the head can be raised to insert the negative carriers. It works perfectly, using the arm that raises the normal Zone VI head. Atleast, this solution works for me, because for smaller negatives, I prefer condenser enlargement. While I've not tried it, there may still be the option of getting an Arista high intensity head for diffusion enlargement of smaller negatives. If this works, it would require the Arista Beseler adaptor, in addition to the Zone VI Beseler adaptor. Circular color VC filters could be inserted above the diffuser by lifting the head out of the housing. Again, I've not tried this.

With these adaptations, the only thing that's not possible with the Zone VI is 5x7 color enlarging. But other than this, I've found the Zone VI to be a very good general purpose enlarger.