i can't give you an honest comparison, because i don't own both. i have a 5, a Junglas, and have played around (a little) with the Izulas i bought as gifts. what i can tell you is - i EDC the 5 and never feel like i'm missing out by not having a more knifelike knife nor do i walk with a limp due to the extra 16oz on my right side. i really like the 5. i have a lot of knives (like most folks here), but if i could only keep ONE (yea, i know, that's freakin scary), it'd be the 5.
i have not dressed out any game with the 5 and can see how it might not be as easy as it would be with a thinner knife, but i really believe most of the negativity surrounding the 5's weight/thickness is exaggerated. i too worry a little about the steep angle of the sabre grind reducing the life of the blade, after 100's of sharpenings. i counter this by using a sharpening method that minimizes steel removal.
i'm not into small knives, though, so keep that in mind. the 5's about as short of a blade as i'm comfortable carrying.