I would keep the speedmaster if it is a case of only having one watch but if you have more than these two I would keep the seamaster. If you only have one watch then the speedmaster is a bit more versatile and can be used for all occations and outfits. I think the seamaster is a bit more sporty so perhaps not as versatile. If you have several other watches then ditch the speedmaster, The seamaster has more charachter, I am not a fan of them in general. The proper answer really, is keep the one you love the most and get rid of the other one.
ditch them both and get a http://forums.watchuseek.com/f29/fs...-watch-3752-50-hesalite-sandwich-2010482.html for only under $3000. you can swim with it no problem and it'll be a much better choice and a happier one for little price if you drop both watches. just my opinion with such a great choice to make
Keep the chrono. The 7750 movement in it is one of the all-time greats, and very few are better hosts than Omega!
If you're set on keeping one (vs. selling both as another option), keep the chrono IMHO. in addition to @Time Exposure's comment, I think it looks better.