I have been bitten by the IWC bug lately and first collected a YG DaVinci perpetual calendar.
Then I added 2 Portugieser watches, including a beautiful Yacht Club SS/RG combi.
I was happy with my choice of IWC watches, but felt that no IWC collection would be complete without a pilot watch.
So, my search for one started..... And it finally ended up with me buying this one, a 5002-01 BP.

I searched for a long time, browsing the Internet and reading a lot about pilot watches. I did a lot of footwork visiting watch stores in Ginza, Shinjuku, Shibuya, and Nakano to compare other pilot-watch sizes, metals, dial colors, and complications. Then one day, I decided enough already!
I chose the 5002 because of its history as the first IWC BP released on the retail market, in 2002; because of its HUGE 46mm size (I like BIG watches.); and because of its well-balanced design with cute "railroad track" power reserve dial and Arabic numerals that incude the "9" but not the chopped-off "2" and "4". Luckily, I was able to procure this very-hard-to-find model, which was available at only 1 store in Japan AFAIK! I am a happy IWC collector, having added this one.
It is dated 2003, so I don’t believe it is the so-called “transitional” model. It has the “IWC” crown and not the “fish” crown, but has the slower movement.
IWC experts can probably comment more on this.