HISTORY:
The Rolex Submariner reference 16800 is a transitional model; bridging the gap between the 1680 and 16610. There was one additional model between these two, the 168000, which was essentially a 16800 with upgraded steel. Reference 16800 used 316L, while 168000 and 16610 used 904L.
Three improvements stand out with the 16800 as compared to the 1680. First, the depth rating increased to 1000ft/300M. Second, the plexi crystal was replaced with sapphire. Lastly, the movement was upgraded. It featured a higher beat and a quick-set date.
In the early years this reference had a matte dial, which was replaced by a gloss dial. The gloss dial, featured white gold surrounds. Both variants had tritium lume.
The caliber 3035 movement featured 27 jewels and a a higher beat than it's predecessor.
Production for for the 16800 seems to range from as early as 1977, to as late as 1989. 1979 through 1985 seems to be more realistic, or an average of dates I could find. Consider 904L steel was introduced by Rolex (per Rolex) in 1985.
REVIEW:
For purpose of this review, I am referring to early, matte dial 16800 models. The later models are essentially 168000/16610's.
The 16800 is an underdog of Rolex Subs. It is not popular among collectors. For this reason, these pieces can be had at lower prices than other discontinued models. Are they vintage or modern? Good question. Definitions and understanding of "vintage" vary. Some would define vintage as any model which has been discontinued, while others might say it is a maturity, which includes the item being outmoded. Regardless of your definition, I think all would agree, the item must have enduring appeal.
I do not care for the reference 1680; the top hat in particular. I have had two 16610 models and did not bond with them either. The 16800, however, was love at first sight. I missed one on HQ Milton's site a few weeks back. It was gorgeously aged and heavily worn. Despite the condition, which would turn off many, I was in love. In fact, as fond as I am of Matt's, it is too nice. I would cringe if it was to get damaged.
One thing I have grown to like about vintage is character. Vintage watches are more than just hollow luxury. They have been proven over time; individually and collectively. They have a story to tell and tell a story about the wearer, even if the watch's stories are not the wearer's.
Many of you know, I have had felt guilty in the past about wearing JLC, the 114060, and a 16613. I realize it is my own issue and it seems silly. Just this week, I found my self concealing a 114060 under the cuff it had slipped out of, while speaking to a peer. I have never done that with a 14060 or 1675. Perhaps this is why the 16800 appeals to me? The matte dial, aged lume and bezel, all project a different aesthetic. Vintage watches, Rolex in particular, don't have the same negative stigma the more modern, common, or flashy models do...certainly not that of the young grad who just blew his first pay check on a Rolex and doesn't know the model number.
As Jeff said, the 16800 is a sweet spot between vintage and modern. Semantics aside, I agree. The 16800 has all the character of a 5513, 5512, or 1680. But, it improves on what they don't have; an improved movement, depth rating, and a sapphire crystal. The crystal is not a deal breaker for me, but there is no debating sapphire is more durable and doesn't need to be restored with polywatch.
The other tangible benefit of the reference 16800 is value. These watches, as mentioned earlier, are not popular. As such, the prices are lower. There are countless posts on the internet affirming this statement. It is not just my opinion.
you know me so well, girlfriend 
