I’m running a Grizzly 1.5Hp Dust Collector very similar to both your two options with excellent results. (I would go with the least expensive option.)
I think the style of Dust Shoe is very important after good CFM. Spindle mounted shoes often leave a gap between the work and the brushes, allowing dust to escape. Shoes that follow the Z-Axis are better, but more expensive and complicated. Deep bowls/dishes are even worse no matter what you use. Chasing the action with a hand vac seems to be about the best combination.
IMHO, it is almost essential to have a small gap between the dust she bristles and the work to maximize air flow. Air flow is what removes the dust. Yes, bowls (or any deep feature) presents a problem because the spindle mounted shoe squishes the bristles and reduces the air flow.
No matter how you twist and turn, no system is perfect. There will always be some dust left on the spoil board so using a hand vac for final cleanup is the optimum solution. My dust collection hose is mounted in such a way that it slides into the shoe and it takes zero effort to simply lift the hose out of the shoe and use it to clean up any bits left over.
High energy bits always have the possibility of flying right through the bristles no matter how much airflow you have.
Air cooled spindles and routers also add to the difficulty in chip/dust collection. Both rely on air being sucked in at the top and blown at the bottom to cool the motor. The higher the speed, the stronger the effect. This air flow blows the chips all over the place, including under the dust shoe brushes. I added a diverter to my Makita and improved the dust collection by a significant amount. I know that many will and have disagreed with this approach, arguing that the diverter impedes the air flow and risks frying the router. I cannot say for certain that they are wrong. I can say that I had the diverter on the Makita for a few years with no ill effects.
To get back on topic, I have an old 2HP Craftex dust collector that I attach with a 4" flex hose to whatever machine I am using. It does very good job.
This might not be an issue on the AltMill if it’s rigid enough but a surprising amount of upward force can be generated when the bristles of a dust shoe touch the work especially when the mill does a 180.
The bristles have to go from being angled one way to the opposite and they have to bend in order to do so if they touch the work. I’ve seen it affect the results of a carve but I haven’t any experience with a mill as rigid as the AltMill.
Thanks for the responses. Was wondering how the actual dust shoe would work as well. The consensus seems to be that you’ll never get it perfect, but managing some of the mess has to be better than currently operating with no collection whatsoever!
There is a huge difference between running without and with dust collection. It gets even more important if you cut MDF. I am not sure what you are asking when you say :
….. it just works and if you have a 3D printer you can tweak / customize things