The orginal Hawker Siddly Harrier was a fast bird and was also VSTOL capable. The Yak Foger pictures with that Harrier GR7 was never very effective outside of use to kill NATO P-3s. It would have been an easy kill for 4th Generation aircraft as well as older fighters (Mirages III/V, EE Lightings etc)
The newest Harriers AV-8B+ and Night Attack AV-8B are more attack aircraft than fighters. The FA-2 Sea Harrier being phased out of RN Service is still an excellent aircraft and is more of a strike fighter. The Indian Navy is very happy with them and the Blue Vixen radar.
There will be three versions of the F-35.
Conventional TOL for the USAF
STOL for the US Navy (larger wings)
VSTOL for the US Marine Corps
While there have been many attempts, the only sucessful VSTOL aircraft has been the Harrier used by Spain,India,Italy,Britain, the US Marine Corps, the RAF and FAA and even Thailand. The aircraft IS very demanding and unforgiving on pilots. It is a maintenance nightmare but starting with the AV-8B and the GR4 in RAF service, the loss rate went down. All users put only the best pilots in the Harriers. I know many Harrier pilots and they love the jet. But there will be bonuses and setbacks for the transition to the JSF. One thing that has greatly helped the US pilots is the use of very capable flight simulators. I have been fortunate to have flown the F-16 ADF (my friends flew the F-14B, I got cheated!!). The simulators mean the pilots can get more time and experience without the risk of lost of life,aircraft and useage of fuel. Also use of the TAV-8B reduces the risk of accident. The Harrier still has the highest accident rate but it and the F16 are low level aircraft with single engines. All have proven capable in combat.