Those articles are just click bait from people that don't know what they are talking about. Anybody that been around new card or mining algorithm releases knows it's WAY to early to make a judgment on Vega. Just like ANY new card, there are no tweaked Bios settings or miners currently. Even with the limited support ATM, some have been able to reach 42 MH/s. I think we will see 50 MH/s+ pretty soon once people that know what they are doing can figure it out.
For an RX 580, I vote for the Sapphire Nitro+ RX 580 8GB. Best card I've had. STABLE with 2250 MH/s memory clock and ZERO HW errors. MSI Gaming X+ are also very good cards, the same cards Angry Chicken used in his 11 GPU ETH rig.
https://www.youtube.com/watch?v=UPGxVUaSdvcI agree with Vann, the sapphire nitro's are probably the best 580's... Personally i'm a fan of single fan blowers.. So I had 12 8GB MSI Rx580's, single fan blower model..until I sold them to renovate the farm with 1080 ti's. However, if i can render any advice..If you're building your first rig.. go with Nvidia chipset.. my GTX 1060's were doing the same numbers as my 580's after a small modification to core/mem. And they put up great equihash numbers, quiet, efficient..
Goodluck mate and let me know if you have any questions/