Just received a new black Promaster Tough ($286.95) and immediately swapped out the included ballistic cordura band for a black Barton Elite Silicone .22mm band ($20). Not a major appearance change, but it is a comfort and water utility improvement in my opinion. Here's what it looks like with silicone band:
The included Tough band is rugged and goes with the watch. But I wanted something better for water/ocean use, lighter, and more comfortable. With the silicone band in place, the digital scale says the Tough weighs 98 grams / 3.4 ounces, nearly identical to a Grand Seiko titanium Snowflake. Watch definitely feels lighter/slimmer with the silicone band. Some people report the included band initially is a bit inflexible but it breaks in with use; I can confirm it takes quite a bit of effort to use the band out of the box. Makes sense it will break in and become easy to use. If ruggedness is most important to you, stick with the included band and break it in, you won't be disappointed.
Here are a couple pics with the original band in the photo for a quick comparison:
As you may see, the original band is a bit thicker, heavier, and I would say it's more rugged than rubber/silicone. It's only been a short time, but I'm happy and impressed with the silicone strap feel, quality and operation thus far. The second keeper has a notch that fits into the band taper, and it seamlessly locks taper and keeper. Great design, especially for water use, but we'll see how long it lasts in lots of chlorine and ocean salt (hopefully many years).
Got this watch because I was looking for a reasonably slim and light water/dive watch. As for ISO-certified divers, forget automatics, there's nothing out there that's both thin and light; it's all wrist dinner plates, which I can't stand and they get in the way. Quartz, the Citizen Promaster Diver was pretty close to a keeper, along with some Seiko/Casio/Timex models, but many of these were just a bit too big, plus they have mineral crystals, which I always scratch on pool/boat ladders, metal lockers, sand grains, etc. Passed on most higher-end stainless quartz models because too big, too thick, too heavy. Took a hard look at the new Nomos Neomatik with metal bands, as well as the Grand Seiko sports models, but they were more watch than I need for a water beater, and I didn't want to pay a premium for the nicer metal bands they come with, knowing I'd be switching out for rubber/silicone.
As a compromise to get a thinner/lighter watch, I decided to forgo the ISO dive cert and the rotating diver's bezel. Focused instead on watches designed for ruggedness, with a screw down crown, but normal weight/size. Read some reviews on these newer Citizen Promaster Toughs here on the forums, with the unibody watch case construction, sapphire crystal, screw down crown, and perhaps being just thin enough and simple enough, decided to get one. Also of note, the Promaster Tough screw down crown does seem to be well made and tightly machined. Upon initial review and use, it appears it will be very effective at preventing water intrusion. This will be put to the test starting tomorrow in chlorine.