Wait...people actually CHOOSE to buy Vega's over basically any other mining card? This is news to me. I always thought they were kind of a joke.
Remember so few people mine with Vegas try to remember how long it took after they came out before any decent miners were released.
I would expect that it takes months after release before they are performing at anywhere near max capacity.
Vegas have always been the best option for mining Cryptonight based coins. At times they were even more profitable then a GTX 1080 Ti; there's a reason why they were sold out and then overpriced everywhere. If they had stayed in stock at the original MSRP then allot more gamers would have them and have been pretty pleased with them too since they offered reasonable gaming value for their MSRP (but not the hugely overinflated crypto prices).
*For example, NVIDIA released the 1070 Ti specifically because the Vega 56 beat out the regular 1070 in it's price/performance bracket for gaming.