Anyone have or have used either of these packs? Wondering if the Wabakimi is significantly more comfortable on longer portages to justify the extra $$.

I don't have either of them but I've been looking both of these packs over as well. If I was doing a long (+15 days), I'd go with the Wabakimi with the internal frame. That design would help my hips support the extra weight of gear for a longer trip. Otherwise, I'd go for the Winish with 5800 cu in. Hope that helps!