HMA2001,
When I saw your post I was thinking somebody had found my old post from this summer, as I started my IWC adventure and my membership here with the exact same question you have :o)
You can find my old post with the great responses I got HERE.
My instant love was the silver faced one, 502213. I ended up buying it and even though I toiled with the 42 vs. 44mm question for quite some time (as I do like larger watches) I have to say that I now know I made the right decision. Sometimes you just have to trust that instant feeling.
The differences I found between the two similarly looking versions were these:
- The earliest versions of the 5022 and 5021 had the 51610 movement, and although I am not sure when IWC changed I know that the 2008 and 2009 catalogues both show the movement to be the same 51613 as the 5023.
- Rose gold vs. red gold as described by Greg.
- The face of the watches have the same size, it is only the bezel on the 5023 which is approx. 1 mm "thicker".
- Due to the thicker bezel it also seems to cover more of the watch mechanism on the back, in other words the bezel is thicker there as well.
- Since you are looking at the black or ardoise dial version the stars and the sky in the moonphase display may be the same. On my silver faced one it wasn't. The 5022 has a special dark blue quartz stone that sparkles while the 5023 one has a more plain blue sky with larger gold stars and no sparkle.
- My 5022 came with a light brown alligator strap while the 5023 comes with a dark brown strap - again this may be the same dark brown for both the black/ardoise faced ones.
You will have your resons to choose one over the other, and price may be one of them of course. What did it for me was that first love with the thin bezel and the light brown strap.
The great thing is that whatever you decide, you cannot go wrong :o)
Good luck and be sure to post pictures - hereyou can see some of mine.