Well, that depends.
1) Power efficiency: SAMOLED holds the advantage when displaying black or lower APL content.
2) Brightness: IPS still holds the advantage in max brightness.
3) Resolution: SAMOLED screens have a lower sub-pixel density than IPS, which makes IPS better at the same resolution. QHD SAMOLED screens are roughly equivalent to 1080p IPS screens, however.
4) Color accuracy: Neither is better than another if calibrated properly. SAMOLED is generally capable of displaying a wider color gamut than the sRGB standard. If the OEM does not provide a proper sRGB display mode, than the SAMOLED screen produces overly saturated, neon-looking colors. Some people like this, some people don't.
Hope this helps.
- Matt Humrick, Mobile Editor, Tom's Hardware