Could be wrong but I read elsewhere that the 226 & 2232 are the same but the 2232GW comes with a glossy screen.
The 226BW is/was a favorite but Samsung started changing the panels internally due to high demand to lower quality ones so it's a bit of a gamble as to which one you will get. There are some options
available if you get one of the lower quality panels.
The 226CW is the newest panel and is supposed to be equivalent to the original Samsung panel 226BW but always with a Samsung panel present in it, I think it also comes with wide gamut as well. Of course they charge a higher price for this, not seen any decent reviews yet either though a few user reviews have been positive.
I'm waiting for BeHardware to review the 226CW before getting one myself.
Edit:
TFT Central asked a Samsung rep about the 2232BW
However, to their knowledge, the SM2232BW only uses Samsung's own TN Film panel at present, and the aim is to provide all stocks with this panel as many users had hoped for.
so it looks like the BW variant has the Samsung panel in it.
Edit 2: BeHardware has posted a
review of the 226CW on their French site, the translators don't do a very good job in explaining it but it sounds like there is something wrong with the 226CW and it's response time & they had difficulty in adjusting the colours of the display.