I would say if the imac pro with the vega 56 can't take the VR game then the 64 wouldn't cut it too. Both cards are almost the same, except that the 64 has a tiny bit more of everything but with the ridiculous high added prices tag absolutely not worth it.
People think they need this extra to make their imac worthwhile - but to be true the only good value for money imac pro (as far as you can say this from mac
) is the absolute base configuration - so due to the extremely high added prices tags of extras in apple store everything else is not really worth it - except you have a special need to satisfy it.
I don't have any experience with VR gaming - but to be true if gaming would be my focus - I would never buy a mac (never!) - windows pc all the way -> you get a much better experience at half the price for sure and you also have much more games to choose from. Since I am forced on a mac (due to iOS development) I am in the lucky position that I don't play games anymore thus it was easy to switch to a mac. Otherwise I guess I would have 2 machines - or accept a less good experience on a mac
Sure there are people buying the iMac Pro with vega 64 and all maxed, because they think they have then a killer gaming machine - but thats absolutely not the case. If you want 4K gaming etc, you need some nvidia 1080Ti - maybe in SLI - which would cost you the half of any imac pro - and would give almost twice the performance in games.
Mac is not really good for games - you can do it and it can do it well - but in my eyes, its still a big compromise - and that was also the reason why I skipped the Vega 64 - because since the 56 is not a high performance gaphic card - the 64 isn't too. And in 1-2 years both cards will be crap compared to any new cards offering out there. So you have to rely on an eGPU anyway.
If they would have added a nvidia graphic card - then I would change my mind and go for the max graphic configuration - because then you would have a high end graphic card. But since ATI isn't high end anyway - why waste money in order to have something a tiny bit better but still far below of high end stuff
Oh and to answer your question - if you want a mac and don't want to use 2 machines for gaming and work - which I totally understand - then I am pretty sure you will get a more than great machine with imac pro - and there is absolutely NO NEED to invest in any of their expensive extras which would give you ANY benefit in gaming
.
Just my 2 cents,
Oliver