Oh I meant reviews that gives you measurable/comparable sharpness result such as MTF number. something like DXO, Photozone, or DPreview. You can then easily compare MTF number between lens A & lens B. Granted, they may have different testing methods, but if all reputable reviewers say lens A has higher MTF number than lens B, then I generally agree that lens A is sharper than lens B. Other websites such as the-digital-picture.com gives you 100% crop comparison. I think sharpness wise TS can also use it to compare lenses.
Other than that.. yeah I also don't care much about reviews that only provide comments.. "This thing is razor sharp!".. or "Booookehlicious!" . Those are almost pointless
I also agree that some things must be experienced first hand. For example, if we talk about lens weight, let's say lens A is 300 grams heavier than lens B. Probably for some this is already too much, but for others 300 grams is negligible.
Btw I still think that TS doesn't need that 20mm f/2.8 lens