I first bought a Zelex doll several months ago. It was awful.
The 1.0 SLE material is hard and prone to tears, and the foam core inside distorted the 'skin' when the doll was bent at the waist. The buttocks were strange looking and looked unnatural when the legs were bent at the hips, and every other part of the doll was rigid and unpleasant due to the foam cores being so big and solid. There was also a 'scar' that had been sewn closed on the doll's chest, likely a last minute repair (not that I minded much.). The upsides: the sculpt of the model was good, the skin felt realistic, and the doll shipped out and I had it within days of my purchase.
Regardless, I wasn't impressed. I also just had a bad experience prior to this doll and so I figured that silicone dolls were just supposed to be hard and unpleasant. Then I heard about Zelex's customer support policy- they were sending out 2.0s to customers who had tears on their 1.0s. My doll had them in the armpits and the buttocks, so I reached out.
I had a new, 2.0 model within a month (after corresponding with both Zelex and David from Betterlovedoll).
The 2.0 is so much better. It's as soft as they advertised, and the foam cores inside are reshaped, so it doesn't push out of the back when bending at the waist, and the buttocks no longer distort unnaturally. The tearing, while still possible under excessive stress, is greatly reduced thanks to the extra elasticity of the 2.0. It's a solid doll and a great way to get into silicone, and I think it's well worth the money.
Overall, I'm very happy with everything, especially the doll. Zelex has great customer support, and it goes without saying that David is always wonderful to do business with. I don't think I will be going anywhere else for future purchases.
In closing: DO NOT get a 1.0 SLE doll from Zelex, even if you can find them cheaper. the 2.0 is definitely the way to go.