Is there a significant advantage to being at an 8 person pod over a 6 person pod?
The number of players in a draft certainly affects the draft, but the effect is symmetrical; all players are affected similarly.

One reason that 8 players is optimal is because the pairings work out perfectly; no one is going to get paired up/down.

From your opening pack you get:


the 1st, 7th and 13th pick in a 6 person draft
the 1st, and 9th pick in an 8 person draft
the 1st, and 11th pick in a 10 person draft


In a smaller draft the signals are clearer, you see the same pack more times. Correctly reading the signals is rewarded with more information about what cards might wheel (come back around to you).

In a larger draft the signals are weaker, you see more packs, but less picks per pack, nothing worthwhile wheels in a 10-person pod. In an 8-person pod, wheeling cards is rarer than in a 6-pod, but still happens occasionally.


  Is there a clear total strategic advantage to being in the 8 person pod over the 6 person pod?


No, if anything the advantage goes the other way; a 6-person pod will favor the players who read signals the best. The large the pod the more it favors card-evaluation skills. Different skills are rewarded differently depending on the pod size.