Like proper undervolting and power consumption, better support when you contact them by email.
Its SIMPLE - UIX Element in app better than nano-element from browser, no capcha, maybe better programing miner parametrs.
I am happy with the support,they answer fast, and may not be very deep in explanations, but you can ask again, and again, and get quick response. Go in the chat, get Mirelle, and start one team viewer, ask for help directly, if you don't need it often, they will not decline. If you know so little about mining, that you need support and help all the time, don't expect them to give you round breaking support and resource, as if it was a million dollar contract for 2$ per rig per month.
Undervolting is good, at least for AMD RX, I don't have Nvidia, but I see it is the same possibility. Speaking from experience, for RX5XX and maybe 4XX cards, you do not need separated undervolting for each card. I have different RX580s, and they hold sifferent OC to memory, others give better MH/s with different core OC, so each different GPU has its own OC sweet spot, and SMOS allow me to do that. Undervolting is only one value, but if one card out of 8 cannot hold 800, you can set the whole rig to Core Undervolting 820- the difference in Watts is nothing. A 6GPU RX580 8GB RIG with OC set to have each GPU mine at 30MH/s on ETH is configured at Core Undervolting 950 in SMOS. This RIG consumes ~940W from the wall. Now the same RIG with the same settings, apart from Core Undervolting to 810 consumes..... you guessed it-940W from the wall.
There were issues with the Group command lines earlier this year, now this is fixed, many things are fixed, and some small details will be coming, I believe. As far as separate FAN lowest % and Target Temperature, there could be some point in doing this, but still, if you sacrifice a card that can be cooled fine at 50% FAN, by setting it to 60%, just because the hottest GPU needs 60%, it is not a bug deal for me. You are always running similar card models on one motherboard, so the difference, if any, would be s.th like my example.
I have been using SMOS since January, and I have been very happy with the fact how much easier, simple , and good for mining is, compared to Windows. Yes Windows is free, but 2$ per rig per month, calculated for a standard 6 X RX470/570/480/580 is about 6 hours mining to pay, at the given time of the comment. Windows is not free, but for miners, I believe it is.