vbPortal for vb3 is not finished yet (soon will be out of beta)
But for your info:
The new installation requires "NO" files of vbulletin to be edited.
Converting vb3 styles to vbPortal 3 is easier.
There are "loads" more features in vbportal now than in any other portal.
vbportal for vb3 has undergone a "complete" rewrite from previous versions.
Because no files hacks during install means vb upgrades are simple.
Also reference cost....
The $20 is for access to the support forums and gives you "Premium Membership" status. If you do not need access after you join then there is no need to renew your membership and you can still use vbportal script. (at time of writing)
And... If you purchase owned versions of vbulletin or photopost or Hivemail via the banners on vbPortal you get Premium Membership for FREE
Hope this helps