I brought my wife (non-metal fan) with me on the this year's 70K cruise and it worked out wonderfully. She chilled on 7 or the room to read and relax and I got to "be metal." I don't have kids (yet) though so that would probably be an issue. You would personally need to sacrifice some time to not be as social to spend time with the fam, but it's better than not going. I realize it's also alot more money to bring the fam...... depends on your financial situation.
I'm very confused on Barge to Hell Vs. 70K. At first I thought Barge was only extreme death and black metal fans, which I am mostly not a fan of. However, when I'm reading Barge also includes Thrash and Doom (my favorite subgenres) I start getting really confused.
Would a band like Amorphis be on 70K or Barge? What about My Dying Bride? What about Testament? What about a band like Arch Enemy or Moonspell? It's all band related to me. Where do these bands fit? I hope it's a clear choice for me. Very concerned about this. I also have no issue with 70K being on a bigger boat ESPECIALLY if the 3rd stage is bigger / higher and Johnny Rockets was replaced with something else :)
BTH is going to be more geared towards extreme metal (Black, Death, Thrash, whatever falls under "extreme metal") but it isn't going to be 100%, otherwise they wouldn't sell enough tickets.