Assuming this is on the level, with the VIP promotion you do get a small surplus of resources which is nice along with bonuses to your gold, souls, and exp.
However with option b, you'll have 0 need for any of that except for traitstone to apply the skills to all troops. In that regard, all the bonuses from VIP are otherwise irrelevant. If you're already VIP 5 then just spend the gems to get the stones.
Either way, seems like a huge reward for beta testing something, to which I'd wonder how can anyone else get in on a deal like that. Generous would be an understatement.