In optics, it's all about compromise, and to get the high transmission rates for low-light performance, something else will have to be sacrificed. While I am not that concerned about the edges, I would indeed prefer a sight picture equally sharp across the entire image area. But the Leica ERi 3-12x50 I had was sharper/resolved better at the edges than the Zeiss HT, the SB Zeniths, Klassik & Polar and the Kahles CSX.
The Zeiss is the worst in this regard. But even the techs there will tell you they strive for the center sweet spot and give up "a bit" on the edges to gain in terms of overall low-light performance.
All of our needs are different, and no two sets of eyes are truly alike, so we tend to arrive at different results at times. But for me, the primary strength in a scope must be an ability to resolve fine detail in the poorest of lighting while having ample transmission to provide a decent sight picture -- not to mention having a reticle suited for such an application .In that regard, the Leica ERi 3-12x50 scores nicely and outperforms others with more "famous" names emblazoned on them. .
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