Bubble bags are fun. Make sure you keep them clean and the screens free of dried resin. After every use, I wash my bags in hot soapy water, give them a good rinse, let them dry, and then dip the screens in iso., wiping them with a clean cloth and re-dipping in iso, as needed. Holding them up to a light source helps you see how clean they really are.
If you want something that's full melt, I wouldn't use dry ice. The basic problem with the dry ice method is the amount of contaminant you'll shake thru the bag with your trichomes. My dry ice runs yield 16—20%. It's a lot less work than bubble. But, the product is inferior. Don't get me wrong, it's still totally smokeable. But, it's not full melt. The problem is, if you use dry ice chunks and you're not super gentle, you'll quickly start pulverizing the cellulose and other non-resinous plant material, regardless of what micron screen you're shaking thru. Next time I run a dry ice batch, I plan to put my dry ice in a blender and fold the resulting 'powdered' ice thru my trim and shake it gently thru a 200 micron bag. I'll then sift that product thru a 160 micron screen. My hope is, if I can keep much of the pulverized contaminant above a 160 micron screen, I can filter some of it out, without pulverizing it any further. Anyway, we'll see...
Now, when it comes to water-ice extraction, your bags will make all the difference. I produced some 95% glandular head 'bubble' 2 nights ago. It's the highest headie percentage I've yielded from my (admittedly limited) 5 or 6 attempts at bubble. I used fresh 'smalls' (B-buds) and 220/160/45 1 gallon bags. Interestingly, once under a 60X microscope, I could see there were no capitate stalks at all...just glandular heads, a few flecks of green, and the occasional non-glandular cystolithic trichome.
Happy hash-making..!!