I have both, and I hate my V-spec. Love my Jammin! Jammin makes same if not more power. was $100 cheeper, and did not leak from every orifice like the V-spec. The V-spec needed a complete rebuild, and reseal, as it had air leaks everywhere. The front bearing sucks air, leaks, and is a piece of Chit. Fuel consumption can be moderated with the right venturi on your Jammin. Go with the Jammin. V-spec sucks.................air!!