I 4box D3 every new season for about a week or two if it's an interesting season. I have done almost every bit of content since beta. I love the diablo series.

My mindest when boxing D3 is not the same as games like WoW. I'm not building an amazing team, i'm basically gearing 1 main character very fast and usually very well. I also enjoy grinding out paragons with the group experience bonus, solo is just not feasible, you could solo for a week and not get as much exp as 4man in a day. I get grind when i want, and all the gear drops are for my class and i can pass it to my main character. The only detriment to boxing 4 is that bounties can't be efficiently split. I usually have to join public games on my main for faster bounties.

no /follow, so i generally just gear the exact same run speed on every character. I avoid abilities that teleport to mobs, and abilities that reduce cooldowns based on things like hit and kill. Usually always a corner nearby to reset stacking.

I play class builds that aoe or auto target mobs. Things like Whirlwind barb, Condemn Crusader, Multishot Demon Hunter, Pet Witchdoctor, WoL monk, Rat Necro. Sometimes i'll switch one character to support abilities. I tend to try and stick to all same class for loot reasons. If you stick to these similar mobility class builds things run smooth and easy peasy.

I equate boxing D3 to boxing mages in WoW. You can not get the mobility or playstyle experience of a solo mage, but it's still viable and you reap benefits others do not.

3 ww barbs and 1 support barb was really really fun this season.