I own both and, I've gotta say, having these two steeds in the stable is a dream. I have to agree with SuperDave's assessment. The Venge is a bit lighter and, in my view, livelier. I've done many fast centuries on it and have had no comfort issues. The S5 hasn't been in the stable that long. I think its added weight and stiffness is noticeable ... But so is its speed. It's a damned fast bike on flat to gently-rolling terrain. It handles better than any bike I've ever ridden. I did one crazy-fast century on it about six weeks ago. I was looking around at folks who looked like they were on a death march and I was cruising and thinking, "this thing is like an unfair advantage. But at 75 miles, when I was one of a handful still at the pointy end of the "ride," we hit a big hill and it was all over. I really felt I was struggling to drag the thing up. At that point, though, I might have felt the same on the Venge. And I might not have hung in to that point on the Venge. Who knows.

It all comes down to what you want from the bike.

If you want pure riding fun, I also have an R5 vwd. Not an aero bike, but fabulous ride quality, very light and lively and still plenty fast.