I have bought a used M8.2 (without any warranty) some weeks ago.
Before using it, I thought about the same questions - M8 vs. M8.2 and thought, the M8 with the faster shutter should be preferred.
Until now, I have never missed the faster shutter and barely scratch 1/2000.
I like, that the shutter of the M8.2 is slightly less loud, but then again, it is much louder than my film M cameras. A even slightly louder M8 would barely bother me.
When using the camera with flash, the 1/250 could well be the biggest difference between the two cameras for having a wider control of light.
So from the differences in functions, I do not prefer either camera over the other.
The 2 year warranty is worth a lot in my opinion (helping you, to sort out ANY issue, that might occur during the next months).
I would opt for the 2year warranty demo for the same price.