5980
2862
Toss up based on lifestyle
I own and wear both often. 5990 on the wrist for travel and 5980 for most other leisure time. I don't wear ether for dress, though I believe either could suit the purpose.
My 5980/1A is a first-run reference (with Geneva seal, etc), therefore blue, and winds my sentimentality wars. I also find myself often missing the 24-hour chrono counter when I'm without it. I guess I like to record things 😳
The 5990 dial is a stunner in its own right and wears a bit bigger to my wrist (more comparable to my 5980/1R)
Either way, you can't go wrong
Good luck