Welcome to the forums…
VLANs have nothing to do with gaming performance. If you want the best latency for gaming, the defaults will provide that. Anything else you add, will add CPU time and latency. Terms like “gaming acceleration” from other vendors are 100% marketing bs, because you can’t accelerate your packets above what your internet provider gives you out of the wall - only delay or drop some of them. Someone replied with a very sensible solution last week in another thread to a similar question: prioritize the gaming console/PC over everything else. That’s the best you can do if you have issues - and unless someone is “borrowing” movies on BT all day, 500M is more than enough for an average household.
VLANs can isolate gaming systems with open ports for added security, but unless HW offloaded, it’s not a free ride either.
http://forum.mikrotik.com/t/using-routeros-to-vlan-your-network/126489/1