I own grill and dye i5. Both masks are great.
The dye i5 is slightly bigger than the i4 which will cover your chin part a bit more. Cool look, kind of like a robocop style. The disadvantage is for people with larger face your forehead will expose but it can be fix with a headband or head protection. Other than than it gives a wide vision on the field since the len is like 2/3 area of the mask.
The grill has a smaller vision coz of it's len being smaller than the i5, aggressive look, offer in many styles and difference colours. Much bigger than the dye i4/5 so your face will be cover more. Has peak if u do want to wear it. The inside of grill has plenty space for people who wear glasses so I would recommend it. Here r picture of me wearing my grill and my i5.
I personally use the v-force grills after trying lots of different masks from marshaling i feel the grills offer the best combination of everything that is needed vision is good, they cover your face well, the style in my opinion is cool sort of like predator and the colour variations are awesome and they can allow the use of glasses.
Ran my i4's for a couple of events now, they are wonderful as far as i am concerned, but like i said I have a fairly small face, So if i do open my open my mouth too wide i could possibly get hit in the chin and I can imagine that should work. but so far so good, And once I got used to it, removing and cleaning the lens is nice and easy.