If this thing is 10.5 long then I'm cutting my HDD cage in half, I doubt I'll ever need moer then 3HDDs anyway ( I have space for 6 at the moment)
Anyway it means better air flow
As out the exhaust being very small I think it will be enough, just means it will come out at higher pressure, which yes could increase volume a small amount, but I don't think by to much, the fan will be louder then the exhaust area anyway XD Air coming out at higher pressure means heat gets further away from your case as well, this could be a good thing.