It has 100's of times better then your average warrier. It has increases in speed and power. This very powerful stage was first reached by Gohan after his vey close android friend was killed by Cell. This has many more attributes then the first level. The changes are that the speed and strength have been upgraded by at least 50 times.
Physical changes result in longer hair, and larger pecs.
This encredibly strong form has major changes from ssj2. SSj2 has slightly long hair, but ssj3 has foot long hair. Also, SSj3 has electrical charges running around it. This stage is the best stage. This is the stage the seperates the men from the mice.