This might be an interesting article for those interested in the original question:
Wether or not it is worth it will depend heavily on a lot of personal factors, like intended use of the image, workflow, budget and muscle strength
Personally I normally use the Tamron 35 mm F1.8 SP Di VR because I like the image stabilization in low light, the good close up range, and on big scans/prints, it‘s clearly sharper than the 35mm F2 Ai-S lens that I used before.

Some New Wide Angle Lens MTF Tests: Sony 24mm f1.4 GM; Sony 35mm f/1.8; Tamron 35mm f1.4 SP
Most of you MTF junkies are aware that I've published all of our prime lens MTF curves in a series of articles by brand, and that I said I would just add new lenses to those articles. I recently tested a series of new prime lenses, though, and thought they were also worth putting up together [...]
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Wether or not it is worth it will depend heavily on a lot of personal factors, like intended use of the image, workflow, budget and muscle strength

Personally I normally use the Tamron 35 mm F1.8 SP Di VR because I like the image stabilization in low light, the good close up range, and on big scans/prints, it‘s clearly sharper than the 35mm F2 Ai-S lens that I used before.