@myminerep You can run rigs doing both Eth and Burst (I have a couple of them), but the Eth mining will impact the Burst mining if you use the GPU miner. One of my primary miners can do 60GB in 22 seconds using jMiner. However, if it's also Eth mining those same 60GB take 115 seconds instead - and no tinkering with priorities will fix it. The average time for a Burst round is 4 minutes, so for me, just under 2 minutes is acceptable, but it's possible I've missed some blocks because of it.
H.