Compared to GTL, PAO brings a major advantage in low temperature fluidity, and a small advantage in oxidative stability.
Compared to PAO, GTL brings a major advantage in cost, and small advantages in VI, additive solubility, seal compatibility, and lubricity.
They are comparable in thermal stability, coking tendencies, volatility, and hydrolytic stability.
Most of these differences can be mitigated through additive technology and blending with other base oils, except cost.
Tom NJ/VA