I'm looking at Seiko's JDM solar radio-controlled watches and two have stood out.
Both have the same dimensions, but as you can see different dials and slightly different shades of blue.
Then there is the material difference. The "world timer" is also made out of titanium (and has Seiko's "Diamond Shield"). The other is good old stainless style. Other differences also include the bracelets, with the stainless steel looking to have better articulation.
I'm leaning towards the titanium "world timer" but would be interested to get other peoples thoughts here.
Links with more info here: