around here the question is more like who hasn't. there are many posts here on the subject. i think i'm on my 5th version of 2003. ver 4.00.21. seems pretty stable so far.
make sure you read the procedures for backing up your rom and using the xdarit software. the procedures are easy to follow. there are big risks to both your pc and phone if you are not carefull. otherwise the procedure is pretty easy. you'll need to pick up a sd card reader to make the backup and a spare sd card wouldn't hurt either.
yorch's does have .21 but its not part of the kitchen. its listed under upgrades. i've been using that version. it seems pretty stable. i couldn't get the sim manager software to work with my kitchen roms.
I've been running TMO's ROM4.01.00, RS6.24.01 for about 2 months. I found the exe file in Xda-Developers Upgrading forum. best beta rev yet. Stable, fast GPRS but still has erases SD cards somehow. Current workarund for this erasure is to set your Today theme to Windows default, nothing else. Not pretty but it works.
I have a TMO XDA 1 with StrongARM processor, ok with PPC2002 & WM2003. Can't remember exact name but starts with RUU..... The exe file contains both the ROM & RS upgrade. Ran smooth for me.
I have ROM 4.01.16 ENG
ROM date: 2/4/04
Radio ver: 6.25.02
from T-Mobile's web site. It
was sort of pulled off, in that it
became hard to find, but some
URL's still point to the download. I set my Today
theme to 'Windows default'.
So far, my SD card has yet to
be erased, though I lock it as
much as possible. However,
after 2 months, my MM card got erased today. All I can say,
is the Today theme bit, may
have limited problem, but not
fixed it.