I’m still not understanding the need for the 6.5" of travel. Even if the Z-slider is mounted at the highest point, there’s only about 5" below the unit so you can’t cut material thicker than that. For height it doesn’t really seem to have a practical difference vs the Z-16. The only advantage I see is if you wanted it 1" higher for removing the bit. Is that really it?
I’m currently considering an 80mm spindle so this would be the time to decide on this or just the adaptor to my current Z-16. Even at the IPP price there’s near a $200 difference. If the height change is really of no use, the only other real advantage is the Z speed giving faster cuts. I’m a hobbyist, time doesn’t cost money so that’s hard to justify spending money on.
The other difference is wait time for shipping. 3-4 months wait for the Z-20, or I could have the adaptor next week.