This is not an “either/ or” condition. This a case of having your cake and eating it too. PenTile RGBW technology is perfectly compatible with all types of wide viewing angle technology such as IPS, multidomain (PVA, MVA, etc). In fact, as a power saver it makes it a bit easier to use a wide viewing angle (WVA) technology with PenTile RGBW since many of these WVA techniques reduce light throughput.
IPS (in plane switching) was the name given to a type of WVA technology many years ago by Hitachi and was licensed to other display makers. Other variants of this methodology are in use by Samsung. Samsung uses a few different types of WVA technologies depending upon the application.
Perhaps there are some who are still asking, “Does a tablet PC that is being used by one person who is looking directly at the display really need WVA technology?”. The answer is a definite yes it does. Even a mobile display is used laying on the desk in front of you or held in your hands. Then consider viewing in both portrait or landscape modes and you realize that WVA capability is a generally a good idea.
So, here is the interesting thing about the new Samsung WQXGA PenTile RGBW prototype panel–it has a very wide viewing angle technology, not so different from IPS. Judge for yourself when you come see this at SID Display Week in LA this week.