I really wish my school had given me the option of doing two 3/4s this year. A few of my teachers last year said I would be able to manage it, enquired about it with director of learning and his response was "we don't offer that here. You should be glad we are letting you do one"
But then of course, I should have pushed for it more because there are some students in my year level of same ability as me who are doing two. Which kind of makes me annoyed, but it also makes me want to do really well next year so I can show the director that I would have been able to handle it. Like my brother, I think not doing two 3/4s in year 11 will be my biggest regret of VCE. But hey, in a little over a year, none of that will matter anymore anyway.
There are definitely pros and cons to doing two 3/4s. Had I been given the option, I probably would have done 3/4 HHD this year as well as 3/4 Food and Technology. Just talk to the teachers about the subjects, talk to your schools VCE coordinator and look at how much time you would be willing to commit to each subject (including your 1/2s) week and weigh up whether doing two 3/4s is worth it.