Sometimes the bags develop cracks/tears/rips at the seams & around the collar. The dust literally can get into & through any minute crevice/nook/cranny - so having a HEPA bag should capture the majority of dust with the HEPA cartridge filter cleaning up anything the bag happens to let through. This means the cartridge filter will last longer before needing cleaning or replacement. The bags are cheaper to replace.
One downside would probably be the higher resistance to air flow through the vac - so it’s not going to move as much air. But with the proper dust boot on the CNC, an uber-high airflow rate isn’t needed.
For keeping dust contained & out of the air you’re breathing, especially when cutting composite-type materials that can create some nasty particulates, I’d say it’s a good deal.
Thanks for that, I’d understood a dust boot was included. I’ll buy the 110v spindle when I order. I’d prefer the less expensive boot, if I can use it with the spindle. Can I?