I’ve owned both of these and they both are great but have some drawbacks. The Seiko weighs double what the Hamilton weighs (and like four times the weight on the metal bracelet!) I loved it on the bracelet but found it too too too heavy on most other straps. I love dive watches though so I would lean that way.

I never trusted the Hamilton to get wet, I read some other people’s horror stories about water and it always scared me. But I swim with watches on and prefer a screw down crown for peace of mind. That being said, there’s just something about a Hamilton Khaki! They have that “it” factor. If you don’t care about water resistance and want something that’s always comfortable and looks great on multiple straps, it’s a winner!

I slightly prefer the seiko but both of these are very good choices. More about the style preference. You can easily have both of these in a collection

Seiko. It can take a beating and waterproof. I started with the SPB147 but ended up selling to and getting the SPB143 since it’s a strap monster (SPB147 also is arguably). It was either this or the Tudor BB58 and no regrets so far.

I would pick the Seiko. The Hamilton will be restrictive due to its color.

Ironically enough, a non-ti Khaki was my first real watch and an SSC813 was my second. An Omega Speedmaster was #3. The Hamilton gets worn the most as my everyday watch (I work from home) and don’t hesitate to do yard work, split firewood, etc in it. Omega gets worn “out” and the Seiko on silicone or sailcloth strap gets worn for water sports and when I want to swap out the hamilton but the Omega is too much. I really like the Seiko but outside if water activities, I prefer the hamilton for everyday use.

I’d go for Hamilton. Not a big fan of Seiko in general…