ye honeslty i prefer in order
1. invision power . because is more complete i think. ok is expensive but have commerce complete and forum and page and blog and all
2. xenforo is new and fresh and very good themes but the problem i find is commerce section. need buy addons and not are very good and have some restrictions.
3. vbulletin is old and not have commerce vb5. its ok only for fourm
i never tried woltlab .
Still looking xenforo license - vb4 and vb 5 - and invision power
too woltlab i can buy