So I've handled a whole lot of cutting discs/cut off wheel. And every time i do try out new ones from different brands. And each time i get some really surprising results. Some can be very fast when cutting steel but slow when cutting stainless. Some may cut both stainless steel and steel but may overheat during operation and very expensive. Some may be cheap and you overlook them and then they just pull a surprise when you use them. They cut buttery smooth and fast but are less durable.
I guess there's no perfect way around these things. Trying to strike a balance between performance, price and sometimes availability is really hard. You can't beat cutting disc to it's game i guess .
Well some favorites from some brands that I've used.
Will be focusing on the thinner series of 9 inches size cutting disc.
Anyone can please feel free to contribute to this topic to keep it alive. I'll also update this list as i use more products from other brands.

1. Kroneflex (by klingspor) - Germany
2. Pegatec scissorshand (by pegatec) - china
3. SALI (by SALI) - china
4. BUILDS PRO (by Builds Pro Tools) -Unknown
5. Rhodius (by Rhodius Abrasive) - Germany

Pics in no particular order

Last pic