Re: 2 Holes/ 4 Holes...
I have a two hose egyptian but they seem to be wide compared to other egyptians i saw. i kind-of disagree that it makes a noticable difference because of the simple laws of physics, air vacuum. If your hose is wide the vacuum is created is bigger and forces the smoke to be pulled in grater rate through the heart.
I did an experiment on this in summer. I used a funnel ( a normal one, not the bowl) as an adaptor for a 4cm hose and tried pulling. WWOOOWW. The smoke that comes in is amazing. It made me choke. SO MUCH SMOKE, maybe too much.
IMO the difference between the draw is mostly made by the Width of the stem. My little HHH has 3 stems but only has one small hose port and draws better than my egyptian.