If you smoke at home with friends, get a desktop. My focusvape's work great in a bong, but its not going to hold up to vaping for more than 2 people through a bong, they got hot when you use them that way.
The desktop, I can plug in and let it run all day if I have friends over. I used only my portables for a couple months through the bong for my lady and I and it held up fine. Both my focus vapes are 6 months old now and work as well as they did when new.