Better picture? Depends on your definition. At present, the only OLED available whose price is merely "Ouch, that's a lotta bread" (as opposed to "Are you freakin' kidding me?") is the LG 55-inch curved 3-D Smart, which sells at Best Buy for $3500. It is a 1080p TV, so is not as sharp as 4K sets. But reportedly with its self-illuminating OLEDs, plus the addition of a "white" pixel to augment the standard 3 color ones, it offers an "infinite" contrast range from true black to sparkling white. The 4K is, of course, 4K-sharp, so has that advantage. I'd expect that, within a few years, we'll see 4K OLED sets of 50-inch size for around $1500, but again that does not help you today.
FYI, Best Buy is promoting OLED by showcasing these sets at thousands of stores this week. Maybe one is close enough for you to visit, and then YOU can tell US what it's like.
http://www.bestbuy.com/site/home-pro...eut=2392442063