OK - for quite some time my lizard brain has been telling me something is wrong with MRR. Everytime I look at the graphs I was convinced something was wrong, but I didn't have the discipline to stay mining on one pool long enough to really be convinced they are up to something. Now, I am completely convinced they are either running a service that is so blatantly inefficient that it negates the 'bump' between mining yourself and renting your hash, or they are siphoning a small percentage of the hashes you push at them 'skimming' and using them for themselves (my guess is nicehash). Why nicehash? You can hide pretty well there by changing your BTC address often and creating multiple small accounts for the 'skimmed' hash. Regardless of whether they are stealing or just running a poorly engineered stratum setup, you, as the provider of hash, are getting screwed and would be much better off just mining your rigs on your own and enjoying it rather than chasing down renters who send 32768 diff shares to your gridseed orbs and complain about the hashrate which will later be refunded to them through MRR's idiotic process of just granting credit and waiting for someone to notice and call them on it.
How did I finally convince myself?
I have quite a few rigs now in various places with various hashrates. A good sampling, let's say - 500MH down to 15MH. I've been mining solo at tbdice.com since the new year and staying on that pool, keeping track of the hashrates on every rig for long periods of time and noting any variances, which were less than 2% regardless of the hashrate of the rig.
Enter MRR. So, I went to the trouble of creating separate workers for every rig, and making sure they were aligned with the same worker info on the pool I'd been setting baseline with. Then ran them without renters for 72 hours. The only difference between before and after being introducing MRR in between my rigs and the pool I had the baseline for.
The results frankly made me think that instead of it being so subtle that I had an inkling something was wrong - I should have had a hole in my head from the sledgehammer that should have been hitting me. I'm going to use my Titan as an example:
496MH at the console, 515 at the pool -- without MRR
496MH at the console, 445 at the pool, 465 at MRR
That 10% loss of hashpower at the pool is more than the prevaling bonus in hash value at MRR - then there's the refunds and partial refunds to consider as additional probable losses from idiot renters who can't be bothered with following the DIFF suggestions.
Best case scenario - MRR is just inefficiently proxying work. Worst case, they are skimming off the top and using that hash for themselves...
Recommendation - mine for yourself - skip the drama of dealing with TWO third parties, and have fun with it. You aren't making extra money renting in all likelihood UNLESS you price your hashes 20-30% above market rates there and are getting renters at that rate.
Questions? If anyone wants to challenge me to so a real statistical analysis for a full week, and will pay me for my losses doing that, hit me up via PM - but suffice it to say I've been doing this long enough to smell a rat in my kitchen.