I tried switching from ewbf to dstm for the 2nd time yesterday. Initially it started out 5-10% faster than ewbf which is awesome, however after about 10-15 minutes it slowed more & more to the point where it was as much as 40% slower than ewbf, at which point I switched back.
I've talked to others that do not have the same problem, yet they were running less GPUs than I am. I have multiple rigs with 13x1070s & 1070tis.