It's not necessarily "for" anything other than reasonable clearance. One can expect that sort of gap to be normal on most watches. Too tight and the bracelets are difficult to remove and install. Try changing bracelets on a Marathon GSAR to get an idea of too little clearance...
I've got a soft spot for Seiko watches. Back when I was a kid in like high school someone, maybe one of my uncles, gave me a titanium cased quartz Seiko chronograph. That watch taught me how to use a tachymeter, and on road trips I would constantly check how accurate the car speedometers were by setting the cruise control at various speeds and then timing between the mile markers. My grandfather on my mom's side gave me one of the first Seiko Kinetic Quartz watches around the same time. I loved the idea of the automatic movement rotor charging the battery. Unfortunately it had an integrated bracelet with a rubber component, and the bracelet was sized by slicing off segments of the rubber! So later on when I didn't have skinny high school wrists anymore, the watch didn't fit comfortably at all. We got someone to frankenstein attach a metal extender on, but it was really janky and kind of ruined the look and feel of it. Unfortunately I have no idea what happened to either of those watches, and since in the last couple of years I've really gotten more into watches, I'm really bummed I don't have either of those, especially the Kinetic Quartz since it was a gift from my grandfather and all. But it was partly talking about those and going to look for them at my parents' house that inspired my dad to give me that Omega Dynamic that got me on this forum in the first place..... But back to Seiko. Like I said, over the past couple of years I've been getting more into watches, especially since I found out that a few friends and coworkers are also watch enthusiasts, and I was trying to decide what my first real mechanical watch purchase was going to be. I settled on the Seiko 5 Sports SRPE53. I love the blue face and the distinct look of the 4 o'clock crown, and the simple metal bracelet would be higher up on the dressy scale than the Casio MDV-106A that supplanted a string of Casio Wave Ceptors as my daily wear watch. I was about to buy the Seiko for myself as a birthday present, but then I got the Omega, so the urge to get a mechanical watch has largely been scratched for now. But I suspect it won't stay scratched for long, because that Seiko is just really nice looking to me, and it would be a nice one to have as the first one I bought for myself.
Currently, this one gets quite a bit of wrist time - probably because it’s an accurate low cost beater and I rarely have to set it because it’s quartz …. …. but I’m very fond of these two, when I can be bothered setting the date.
Yes and no. My lose interpretation of the history is as follows. Originally they competed against each other in the market as separate brands despite being owned by Seikosha(or something like that). Grand Seiko was created with the purpose of being the brand which was tasked with pursuing holological excellence and they had their first reference in 1960, with what's generally known as the 3180. Then Seiko was the catalyst for the quartz crisis and Grand Seiko sort of withered on the vine and was shuttered. In more recent times Grand Seiko was resurected as a brand with the Spring drive being a major differentiator which put them on the map again but Seiko was still retained on the dial as a sort of co-branding exercise. In 2017, Grand Seiko was officially separated out from Seiko to be operated as a stand alone brand and the Seiko branding was dropped off the dials to fully reflect the stand alone status of Grand Seiko. So basically, as of 2017 they are indeed separate brands from my understanding.
That would be to fully facilitate a periodical thorough wash and rinse of the watch to help prevent a build up of nasty germ factory funk in behind the endlink. It's a feature of the model one might say Besides, all their bracelets leave something to be desired regardless of brand. IMO. So I only ever have them on straps and endlinks are redundant
Favorite Seiko? Definitely my beloved 1986 6309-7049 which I purchased new in 1987 at the NAS Whiting Field Navy Exchange during U.S. Navy pilot training. I wore it during pilot training, while flying in the fleet…and I continue to wear it at the airlines…as well as today [see below]. It was [is] my first “pilot watch”.
These are the 4 I have. Love them and they find themselves in regular rotation even though they go against other "heavy weights" from my watch box
1970 #2 Seiko gets the wrist time while Omega gets Case Refurbished and new Crystal, Gaskets and Misc stuff done.