As far as I understand, Suprnova does not support Stratum for Ethereum. They mention Stratum on their help page, but all their addresses contain "http".

I just installed, cleared my dag files. Left everything default.
Miner started in etha -1 for slower cards. (auto is default)
results
asus R9 270X 2 gb 13.327 to 13.308
msi HD 7850  2 gb 12.283 to 12.600

mining at ethermine.org and mining ethereum only

So I'm kind of meh.
New to ethereum mining ( but to gpu mining and tweaks that can be done) in just last few days.
Going to try some different pools and such.

My 270x are loosing 1%-5% performance with this new version. The same for 7870  

My 7950s are gaining 5%  

Final balance: Not worth the change, at least not with default settings.

Tried -ethi -8192 but it was even worst.

Maybe I'll try to run simultaneous instances; one for the 7950s another for the 270s

On the 290x the speed was the same with the 15.12 and the 16.12 drivers.

My rigs are optimized with Win 7 x64 and Catalyst 15.12. Trust me, I've tried more than once. But it not a big problem; I'm now running one instance for the 950s with V3 and another instance with V2 for the 270x

Note: I have 5 absolutely identical MSI 270x and they all produce different speeds. Go figure...  

Here with 3.0 im getting better results with 7950/7970 when dual mining, before it was lowering the eth, now when dual mining its stays close to the solo numbers With 2x 7950 and 1x 7970 im getting 61mh eth and 1200mh dcr. Good job Claymore

How to understand, which particular card is GPU0 etc?

Nano - i120, 28мx/1672мx
290X (1018 core, 1250 mem) - i70, 27.9мx/976мx

driver 16.4.1

As I suspected... DAG recreation won't improve V3 performance