I found this to be a difficult decision as well. Of course, as with everyone I would prefer the bigger display and battery without the extra weight and size, but the 16" inches (no pun intended) dangerously close to my minimum threshold of portability while the 14" still does adequately in display size and battery life.
Admittedly, when on the go, the display size of my current 14" laptop has occasionally felt limiting, but I've always managed and it's virtually never posed a productivity concern for what I do when away from a dedicated desk. Ultimately, I realized that I usually connect my current laptop to an external display when I'm in "work mode" anyway, because I find it uncomfortable to work for longer periods of time without a monitor at eye level, an external mouse, etc.. A somewhat larger laptop display doesn't substitute for this use case which defines a lot of my laptop use, even if it may be a marginal improvement in ergonomics due to the taller display.
More importantly, I notice the weight of my current laptop, which weighs nearly exactly the same as the 14" MBP, many times a day. Whether it's sliding it into my bag, lifting it out onto a desk, using it on my lap, or moving it to a meeting, the convenience of securely holding my laptop with one hand/arm or balancing it on my legs would be compromised with the 16" model, and I expect I would just end up not having it around as often. This is without even accounting for the heavier/faster 140W charger.
Besides, the MacBook's 14.2" 1.54:1 aspect ratio display is about 8% bigger in area than my current laptop (14.1" 16:9), mostly due to the squarer aspect ratio. This should already be a slight but noticeable improvement, so I don't expect I'll be disappointed by any sense that I'm upgrading to a display of the same size.