After 2 days using Bminer v.6.0.0 I noticed a slight decrease of rejected shares in comparison with previous versions, but still a little more than in DSTM(
And what about the performance? Well, on my system, it is the same as with DSTM - no less but no more as it should be (as it report in console).
In my own opinion maybe Bminer sending more than 2% to developer and that is why my hashrate on the Pool is 5% less than miner report in console. While the DSTM miner, in the same system, give me only 2% less (as it should be).
For now I will stay with Bminer because it is more stable on my rigs, but I hope the Developer will improve his miner in the next update and we all will have a really fastest Cuda miner for Equihash)