I've had dealings with both markers and in my opinion the G4 feels better in your hands. It's more ergonomic grip slides into your palm with a more natural feel and it's longer barrel helps you to sight your marker a bit better than the Mini. That being said, the Mini is extremely air efficient and has an ultra smooth and quiet shot. It also offers a tighter feel for those who prefer that. Which marker do I prefer? Well I'm a feel guy so even though my Mini shoots better than a G4 and is more reliable, I have to admit if I could do it all again I'd buy the G4, regardless of any maintenance issues, because it just feels more natural in my hands (of course I shoot an '08 Ego now so buying another marker is a moot point).
It really depends on your head size. For me, the Dye i4 is extremely small and doesn't cover half of my face. If I had to choose between the two I would choose the Profit but it ultimately comes down to what best fits your face and what you're most comfortable wearing.
Last time i used an 08 i got about 7-9 pods on a 68 and your using a 90?
I know that's pretty interesting. I get about 6 off of my 50/4500, and my local fields only fill to 3000. It's interesting that the leak (or the issue rather) is causing such a drop in efficiency without being readily identifiably. Strange little glitches, lol.