We went to the family plan as soon as it was offered. Someone probably has more details on the pricing, but I think the price for the family pack of 4 was about the same as two golds. At the time, my husband and older son had time remaining on their gold accounts and mine was due to be renewed- so we did the family plan and it gave us credit on their remaining time for merging the accounts (hope that made sense).
As far as issues, I haven't had any that weren't easily sorted. I think we had an issue with entering Cod elite code (but resolved it by entering on website). I do think it's slightly annoying that the primary member has to purchase points and distribute them to the other accounts (might be a setting to change to fix it, but idk and I havent bothered to look).
For what it's worth, we like it.