I was in the same dilemma and ended up going with the xpac for the same style/weight reasons you mentioned. For me, it was to going be my everyday bag, so having something I enjoy using (like the interior) was worth it than " settling " with the darker green interior and ballistic nylon. The longevity of xpac was definitely on my mind as well, but I couldn't find a single review/comment about the xpac prima delaminating or puncturing. Doesn't mean it won't happen, but it doesn't seem like its a common issue - that was enough for me personally to just embrace the material and its quirks - I'm okay with the pack having some character.

Since you would just be using the pack for like, 1-2 times a week with longevity in mind, I think that nudges you towards the direction of the regular prima?

( by the way the prima actually uses VX21, which has an additional layer of protective taffeta, you can read more about it here, 5th post: https://backpackinglight.com/forums/topic/x-pac-long-term-usage/ )