I'll be making the official Mario Kart 8 NeoGAF Community and unless people say otherwise, I'm banning Blue Shell. No matter how they try to "balance" that item, it always will be an issue for racers in first place since players who usually get it are those who don't really get too much benefit from it (5th place or so) It's not fair you get third or forth place just because a guy in last place got it.
If you ban the blue shell, you can look forward to boring races where whoever gets into 1st in the first 15 seconds wins the race every time, provided they aren't absolutely awful or using a troll vehicle.
The blue shell exists solely to counteract the massive advantage 1st place gets by both being immune to everything that's not a power item and being able to drop items. If you drop an item, you gain time on the pack, either because 2nd place hits said item or because they have to drive wide to avoid it. Do this once every two or three corners, and you get a good 2-3 seconds of lead per minute at a minimum, right up to around 10 seconds per minute if it's Bowser's Castle and you get a lot of fake item boxes. You don't even have to be good at placing items around corners, they just have to be on a racing line that other people have to take to keep up with you.
This is also why blue shells that hit players other than 1st and people immediately near 1st should not be in the game. The point of blue shells is to make it so 1st has to actually be good at the game in order to win, and hitting other players just softens the blow and makes it easier to hold 1st after being blued.
The only thing they need to do to balance blue shells is to add a timer (sort of like the one used for lightning) that makes it impossible for blue shells to appear within 20-30 seconds of each other. The MKW incarnation is by far the best blue shell in the series for what it's supposed to accomplish: you can dodge it only by giving up your ability to attack people behind you.
Regarding benefit to the user: by using the blue shell, the player immediately increases their chances of winning the race. If you throw a blue shell and later win the race, you won entirely because you got that blue shell in most cases, especially if the guy you blued finishes within 3-4 seconds of you (since that's how much time a blue shell costs its victim on average).
