I had to install miner on my friend's PC that is very slow single core Celeron with 1GB of RAM and RX470 x 2 cards. Silentarmy gave me only 7Sol/s per thread, so around 28 Sol/s for TWO RX470. The limiting factor was CPU and bus. I replaced the MB by a better one and got double performance - around 56 Sol/s. Still not a lot since the same miner with H81Pro BTC and G3240 gave more. Replacing the miner by CZM (let me call so the Claymore's Zcash miner further), I've got 90 Sol/s on that slowest mobo with single core CPU.
So I hope mrb will pay some attention to this. Otherwise his miner isn't slower for modern cards. Can't say so yet for 79xx. But have to admit that 50% of success of CZM is remote management + telemetry, stability and easy use on all platforms. That pays for itself. And with the same performance people will use CZM just for that.
As for me, I would use freeware miner and add telemetry scripting if necessary. But of course, we now need the same performance just to stay in a line with the majority.