Biggest advantage (not the only) of the Triade over the YiHi is the battery life. Yes, it's larger, but the form fits your hand well. It will also hold ridiculously large tanks without overhang if that matters. Both are excellent at temp control, but to get the most out of the DNA board, spending a bit of time with the eScribe PC software to customize your setup is a really good idea. And if you're into playing around with that the possibilities of vaping amusement and software is loads of fun.
I believe the Triade was the only 3 battery mod on your list. One other advantage on it is 2A charging, which on a 3 battery mod, is quite helpful. And as it was originally designed for Lipo use, the charging is extremely reliable and properly balanced. My DNA mods are the only ones I really trust to charge via usb.
If you end up getting surprised with the YiHi, you're also getting a superb mod, slightly different featured, but with it's own benefits. Either way, happy birthday!