Nowadays they're the same thing.  

Settling with "Insufficient Power" was misleading as it mistakenly led some to believe that, in certain conditions, you could "power out" of SWP.  Absolutely wrong. If you find yourself in fully developed VRS, any application of additional power will dramatically increase your rate of descent.  The previosly touted Vuichard maneuver will hurt you bad if performed even slightly flawed.  Directional flight (fwd, aft, left or right) is the only way out of VRS.  If you have progressed past the initial buffeting in the descent, DO NOT add power.  
If you have not seen rates of descent greater than ~1000 fpm in training for VRS, you have not been in VRS, you have been trained to the "recognize onset" stage, which is perfectly fine.