Also:
R4iSDHC.com's white dualcore flash card, and r4i-gold.com's new "Pro" card are identical. Their firmware's are interchangeable. r4i3D almost has the same kernel, only difference being the savlib.dat and infolib.dat file sizes....leading me to believe it is the same card.
R4i-gold.cc, Ace3ds, r4i-sdhc.com.tw, r4-v.com, r4i-sdhc.hk and r4i-gold.hk have identical kernels. The only difference among them is a name change, of a root file present on all of the kernels, its size is 253kb. The r4i-gold.cc has that file named twice, once as "config" and once as "r4i.3ds" The Ace3ds has it named: "config" and "3DSCARD.DAT", r4i-sdhc.com.tw has it named once as "TTMenu.dat", r4i-gold.hk and r4i-sdhc.hk have it named (3dscard.dat, config, iLL.iL, R4i.3DS, R4i.TP, and ttmenu.dat)
ndsill.net is the same exact card as r4igold.cn The kernels are interchangeable.
r4i-gold.com (3ds version, not Pro) and r4i-gold.eu (3ds version) are the same exact card and the kernels are interchangeable.
r4i-blue.com is the exact same kernel as r4ill-net.com. Only difference is the 835kb file is named "ttmenu.dat" on the r4ill-net.com and its named "R4I.HK" on the r4i-blue.com
r4i-yes.com is the same card as r4i-advance.com The kernels are interchangeable.
I'm hoping this info comes in handy in case a website goes down or you want to use a kernel that is more updated than the one you have. I don't know if it's possible, but maybe the update file from one card might work directly on your card, increasing the compatibility with higher Nintendo firmwares.