Switching regulators create RF noise and it was enough to degrade receiver performance back in the 1990s. I suspect that is not a problem with modern receivers operating on 2.4 GHz. Linear regulators have fewer components and are very stable and reliable. They are almost indestructible, they can even be shorted out and still survive. One very important feature is their ability to isolate the power sources if operated in parallel as in a redundant battery pack system.

The Jaccio is available at both 5.7 and 6.0 volts as well as 5.1. They only require .2 volts overhead. The 5.7 was selected for 5 cell NiCd packs so they could operate down to 5.9 volts. With 2s LiPo packs down to 7.5 volts there is plenty of overhead so the regulated voltage should be as high as the servos can take. I'm running 6.3 on JR servos. With LiPos there is a potential of overheating if your average current is too high, but that is not a problem in pattern planes with 5 or 6 servos, especially if it is electric powered with low vibration.

Jim O