My first Sail was a North. In the long run I am also trying to get away from North and go with a company that just keeps things simple and working.
Yes, I recognize this soo much. North/Duotone is a very innovative brand, this has advantages and disadvantages. If you like it simple and working long-term North/Duotone can be a bit frustrating. This is the reason why I am on Loft Sails Switchblade now. I actually don't think my Loft Sails Switchblade are the very best (in performance) sails I have had. However the Loft Switchblade is a low/medium tensioned sail and works on the very first Loft Sails mast up to the newest mast, even other brand constant curve work fine. I also have (had) a few Loft Oxygens (no-cam), I like these sails. My loft sails last a long time and thay are simple. Loft Sails scores high in simpleness and durability.
I have also used Neilpryde, Severne, Point7, Challenger, GA(astra) in the past, these brands score a bit less (in my opinion) in simpleness. I believe Ezzy has also (maybe even better or the best) simpleness and durablility. I believe Ezzy has (one of the most) durable/reliable masts. I personally don't like soft saildesigns (like Ezzy), so I won't buy this.
I actually don't know what I would buy when my Loft Sails are end of life, maybe new loft sails. My brother advices me to buy Neilpryde ;). It depends at that time. I look for a sail with a certain feel (direct/efficiënt) AND an transparant (as much as possible) luff. I like good visability in front of me. The newest Loft sails (and Neilpryde) have nice colored panels next to the luff, it looks nicer, but I don't see this as an improvement.