willski
1171
I guess all Rolex sports watches are substitutes to a degree.
I have similar, to you, also a 5513 and 116710BLNR.
The SD43 is (to me) a great modern Rolex. The beefed up proportions all around (bezel, bracelet to 22mm etc.) make the it more ‘balanced’ and for a 43mm watch it wears great. The movement has a lot of goodies, and the 72hr power reserve is really useful.
Go for it! 
Considering buying a Sea-dweller 50th anniversary would welcome opinion from forum members
I do not mind the cyclops at all and of course not minding the 43mm size for my tiny wrist. I own the 44mm Deep-sea blue though I do not wear it often. Most people said the Deep sea is too big and too thick for everyday wear, I found it very comfortable t...
The SD Anniversary is exactly what it says on the tin:
an anniversary model. If it would be a regular model your objection to say it is nearly the same as your DS would be correct. Buy it: I love mine! Best Moritz ...
If you have a small wrist...
why not the SD4K instead? I have also had the Deep Sea and while it was fine, I did go back to my 16600 Sea Dweller eventually. The SD4K seemed pretty low production, I’d prefer that over paying premium for the Ann. 43.
I guess all Rolex sports watches are substitutes to a degree.
I have similar, to you, also a 5513 and 116710BLNR. The SD43 is (to me) a great modern Rolex. The beefed up proportions all around (bezel, bracelet to 22mm etc.) make the it more ‘balanced’ and for a 43mm watch it wears great. The movement has a lot of go...
It’s a really comfortable
watch. Get it for sure. I find it very similar to my hulk and a little easier to wear than the deep sea ...
I have owned a 1998 SD4K
since I was 25. Not a fan of the Anniversary model as a result of having the SD4K 5+ years. No telling how long production of the 43K will be, but I suspect not as short as the Kermit Sub. My guess is, you have 5-6 years to make up your mind.