I've got both. Prefer the 2.5-8 over the 3.5-10 for what I do. 3.5-10 cost more, at least mine did.
I like the 2.5 for early mornings and twilight, although in a pinch I bet the 3.5 would work fine. Eye relief is not a factor on either especially on the low end.
I have the 2.5-8 on Kampfeld 250AI and the 3.5-10 on a Kimber 257Bob. - - Both work great.
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below the line feedback
I have a few Zeiss 2.5-8 that I prefer, but my damn bolt handle hits the power adj when I use talley extra low.