I decided that my romisen RC a4 sucks for edc because it wont stay clipped to my cargo pants pocket. My l2i doesn’t have a clip which is too bad. Love that light. My 502b is almost as bad as the romisen and doesn’t stay put. My c10 isn’t made for pockets. That left me no choice but to buy a 2011 model sf l2 and sf pocket clip. Hate it when I’m left with no options! ;^)
Practicing the story for your wife are you? 
Hahaha... yeeeaahhh J)
I'm surprised the 502B wouldn't stay put. That's a pretty stiff clip.
You'll enjoy the L2 though. What color did you get?
The 502 has a decent clip but it is too small for the size of the light IMO. I bought the standard flat black 2011 model.
There are at least 2 variants of the 502 out there (at least), I have one with a thin,floppy clip and I had one with a thicker, stiffer clip. (and please no "that's what she said" jokes ;-) )
A little late, but you probably could have bought just the Solarforce clip and used it with your Ultrafire 50X variant lights. I believe it would work. In any event, you will be very happy with the new L2. A very nice host.
Guess I got the thin floppy clip. HELLO!!!