I've had the Helix Organic and the RTS Twin Friction - All I'll say is I had 2 Helix Organics, before going for the RTS.
The RTS feels so light compared to the Helix, it's an almost stock like feel. Much stronger too. I was running 465lbft of torque at stage 2, and it coped just fine. Now I'm stage 3, I will be upgrading it to the RTS Paddle which feels identical I'm told. The current RTS is dealing with stage 3 fine, but I'm not full throttling it just in case, as the torque will be well above the limits of the clutch.
I've no experience with Sachs, but plenty are running with them and they have been the 'go to' one for some time.