I am a watch collector and own a wide range of timepieces, from Swatch to Rolex.  My first impression is that it really looks like my Rolex Submariner and GMT II. It is beautiful, of that there is no doubt, but I won't sit here and tell you it is a better watch than my Submariner. These are my thoughts when I compare it against the Submariner.

Pros:
1. Day/Date - You can immediately see if it is Monday or Tuesday. Like the Submariner it has the day of the month.
2. Clear case back - I love Automatic movements and it is great that I can see the mechanical wonder inside.
3. Smooth Bezel - The bezel rotates very similar to the smoothness of the Submariner. I was really impressed. I have a TAG that has that annoying click when you turn the bezel. Just like the Rolex, the Bezel has no play, and is not loose.  It stays put and does not wiggle, unlike the TAG.
4. Looks - It resembles the Submariner so much that my 5 year old could not tell them apart. Absolutely elegant in my eyes.
5. Legible - Since it is like a Submariner, it very easy to read. Very clean face.
6. Very bright at night - This glows almost like my Submariner. I actually cannot tell them apart at night in the watch box. Very difficult to tell them apart.
7. Bracelet lock - This has a clasp lock that will prevent you from accidentally causing the watch bracelet from opening and falling off. I have dropped my Rolex a few times because of this. You need to press both buttons to unlock the clasp. I really like that.
8. Weight - It weighs about the same as the Submariner from what I can tell, I did not weigh it on a sale, but I cannot tell which one is heavier.
9. Detail - The attention to detail is very good. No rough edges and the links line up perfectly and looks almost identical to the finish of the Submariner.

Cons:
1. The steel on this is just like the Mid priced Swiss Watches like TAG. It is not as hard as the steel they use for all Rolex watches.  So it will need buffing out once in a while.  It has no scratches yet though.  That being said though, that is one reason Rolex watches are more expensive than a TAG.
2. Accuracy - This is not a Chronometer so the time will drift a bit more than Rolex. But not by a great deal. It will need adjusting every week. But then again, If I do not use my Rolex for a couple of days, I will have to adjust the time anyway, so not such a big deal.
3. Crystal - I believe this uses a Mineral Crystal whereas the Rolex uses the hardest Sapphire Crystal. Only something as hard as a Diamond can scratch it.
4. Diving Depth - This can only go 100 Meters deep.  But then again, I do not dive, so I do not care.

Summary:
I love all my watches as they all have a unique character, but this has become my everyday watch, and I love looking at its face. I use this more than my Breitling Navitimer, Omega Seamaster, or TAG. Just beautiful.

******UPDATE October 24, 2012*****
I love this watch so much, it is the only watch I wear now.  My Submariner is now in my safe and has not seen any use since I got this Seiko 5.  There are still no scratches on it even if I use it all the time.  I always receive compliments for my Seiko.  I really, really love it.  Why didn't I buy this sooner! It would have saved me a lot of money.