Hi Lnr103,
A forum search on Spindle (you can just click this) will bring up some feedback about them. Spindle is relatively new but Neal has some “deep roots” in the industry and I think highly of both him and their mattresses. The quality of their product is certainly “up to par”. They use either synthetic (with a small percentage of natural latex) or 100% natural continuous pour Dunlop made by MountainTop Foam which are both very good quality and durable materials (Note: Spindle is now only using 100% natural continuous pour Dunlop in their mattresses).
You are certainly looking at some great final choices and it would be difficult to make a “mistake” 
Phoenix