JSF VTOL revolutionary?
The novelty with the JSF is that the lift "engine" is not actually an engine -- it's just a fan, driven by a shaft from the low-pressure turbine in the primary engine. In contrast, the Yak-38 had two engines dedicated to VTOL. The advantages are lower complexity, lower noise, lower weight, and lower exhaust temperature and speed (less surface damage).
Is the JSF more "brute force" than the Harrier? Basically the Harrier takes its raw thrust and steers it downward. Since the thrust needs to act through the center of gravity during VTOL, the four nozzles are up at the midpoint of the aircraft, instead of at the rear. This precludes afterburning and moves the engines forward, giving the Harrier its characteristic, front-heavy appearance. This, and the large engine inlet area compromise performance in the high-speed forward flight regime, limiting the Harrier to subsonic speeds.
VTOL prefers a high bypass ratio (think of a helicopter), i.e. a large fan. With the JSF, you have a single engine, but with two fans, each optimized for its respective flight regime: the high-bypass-ratio (1:1 !) lift fan, and the low-bypass-ratio (0.2:1) forward fan at the engine inlet. This is why the JSF has twice the vertical lift as the AV-8B.