We recently shopped for an OLED and originally was looking at the LG but once we got to the store, we also compared to the Sony and the Samsung. We liked the Sony picture best, but they didn't have the size we wanted in stock so went with our 2nd choice the Samsung. The LG definitely had the least "sharp" picture of the three. Been very happy with the Samsung the 1 month we've owned it.
Congrats on your purchase! The Samsung OLED was second on my list, but even on sale it was a tad pricier than the LG C2 (the 65" model). Love my TV now, but I just need to find better (higher-res) content to watch!