Ive had the gw5600j-1 for 5 months.  I am not a g shock fanatic. Obviously many of you are out there.  So this is my initial opinion which is likely to be edited in the future after further use.

Why 3 stars?
I am happy with the purchase and have no regrets.  However this is not a practical watch considering the cost and function for my use.  I don't climb mountains or participate in any extreme activity.  Im a regular guy that wanted a simple watch.  This watch is simple and not flamboyant like a frogman or anything of the sort but it is larger than what i am used to.  For 12 years I have worked outside year round in temps that range from -15 to 108 degrees fahrenheit.  Rain, snow, heat, cold.  I have used the cheapest timex expedition I could find that was low profile and digital/analog.  Recently the band broke and no replacement was available.  So I purchased a more expensive g shock to give it a try.  So far I am satisfied but not impressed.  If you are looking for a low profile simple watch that performs the normal digital functions then I would not recommend this g shock or any g shock currently in production.  The 5600 series is the thinnest g shock currently being produced and it isn't low profile unless you are comparing it to a category of watches in the large profile, i.e. g shock group and the like.  The weight is fine, the band is a little narrow, the width and height is too great for my liking.  The countdown timer is 1 minute to 60 minute range, far too limited.  The appearance is basic and simple (which I like) and it won't make you like a special ops want to be.  I do assume that the watch is well made and protected.

Pros:
Simple, light weight, alarm, stopwatch, world time, atomic time sync, solar technology and battery recharge.  Works as described so far (havent had it long enough to be judged adequately).

Cons:
Too thick and wide.  One star removed.  This watch or some variant should be available in a lower profile.  I really wish the g056 model was still being produced.  I think casio is a good company but they should include at least one model in the g shock family that has a profile that is 11mm or less.  They had the design and production already in place but they obviously determined it wasn't profitable enough to maintain.  I don't like that.  But what can i do about it.
The countdown timer is capped at 60 minutes and will not include the seconds to be set.  Considering this is digital I don't know why Casio would limit the min/max range of this countdown timer. One star removed for this reason.
Watch band is too narrow.  16mm  apparently.  I prefer a wider band.  No stars deleted for this reason.  However the band is too expensive, $25 for replacement.  This seems excessive considering the watch costs $60-79 dollars retail.  Plastic and production isn't that expensive.  Others have had difficulty finding a replacement for the band.  This is without excuse.  A black resin band should be universal for the 5600 series.  Poor decision Casio.
Buttons are not easy to push.  However i didn't remove any stars for this reason.
Beep upon button push should have an on/off feature.  This is a serious annoyance.

Pros:
The screen is viewed easily enough (not  a big deal but worth noting).  Date OR day of week viewable in time keeping screen, Fine with me but should include both when compared to cheaper watches.  Stopwatch, alarm, world time, snooze capable alarm, and full screen illumination.
Simple design.  Way too many g shocks look silly because of the basic design.  Come on Casio not everyone wants a watch that looks like it will have a self destruct and tactical laser equipped.  Give me a sturdy basic simple watch.  This watch looks ok but still way too thick for my preference.  13.5mm thickness is the maximum in my opinion and this watch is just that.  Any bigger and I would return it.
Atomic time calibration.  It worried me at fist but it has sync'd each night that I have owned it.  One night I kept in on my wrist, not on the window sill, and it sitll sync'd.  I live in Michigan.  When i took it out of the package it showed that it had been over a month since the last sync and the signal strength didn't even register one bar.  However by midnight, when the signal is strongest, it must have been adequate to make a proper sync each night.
Solar battery recharge.  Too early to tell if it works well.  Or if the battery holds out.  Never the less this is one feature that I do support adamantly.  I am very much in favor of renewable energy.  Any tech that relates to photo voltaic cells is in my favor.  I purchased this watch to support this technology.  Regardless if it sucks I want to see more renewable energy used so the tech will get better and cheaper.

Conclusion:
I used a Timex Expedition digital/analog watch for 8 years.  It was thin, classy, and has better digital functions than this gw5600j1.  It costs only $15 dollars.  The watch battery never needed replacement despite being subjected to year round outdoor abuse.  The band finally broke.  Specifically the small strap that would hold the watch band in place.  I  actually prefer that Timex watch to this one because it was so much thinner and the countdown time worked better.  However the band was not available for replacement and that irritated me so much I decided to switch to Casio.  So here is the meat of the summary.  My old timex was $15, my new g shock is $75.  I could buy 5 timex watches for the price of this one g shock.  Which is equivalent to 5 timex watches.  If each timex lasts 8 years then that would be 40 years of use on an 8 year rotational timex measurement.  Will my new g shock last me 40 years?  I doubt it.  So from a cost benefit analysis I think a cheap watch will over perform this g shock any day/year.  Time will tell......

Edit-- Now had the watch for 5 months.  No change.