I have put a good 1000 miles on my Venge now and can advise that as discussed, it is a mixed bag. I really like the bike in certain situations. Fast in group situations and solo, brilliant in sprints, climbs better than I expected and way better than previous aero bikes I have ridden due to the massive and stiff BB area. The bike needs speed to come alive and typically, the faster you ride it, the faster it gets. The only caveat I can level at it is that at slower speeds it can feel a little less alive than other bikes, but that is by design.
I tend to ride my Venge on fast 2-4 hour rides and then grab the Tarmac for 60 mile + roads.
Typically, my data advises that overall I am no faster, but it is a game of aggregate where the Venge holds speed better on certain roads and also makes my riding perception of speed faster imo.