Here's a noob question: Why would anyone want to change the rear shock anyway? Isn't the one supplied by Brammo good enough? RaceTech's website make it seem like their's is 10 times better than the stock shock, but does it really make all that much difference?
One of the perennial activities of motorcycle owners is tinkering. There's not too much to tinker with on the Enertia (until someone cracks the motor controller software) so that leaves us with suspension, tires/wheels, chain, handlebars, lighting, baggage, color and not much else.
Is the Race Tech suspension better? All you can do is read the reviews. I'm not planning on changing anything like that on mine as it is adequate for my needs.
Suspension is always a controversial subject, however heres the story.
all manufactures build a product that will work for everyone, from ride position to tires and suspension.
someone who is 5' 8" and 150lbds will fit a bike better than someone like me who is 6' 4" and 260lbds and that is why aftermarket companies are out there, you can get bars with different angles, length and height and companies like Race Tech make suspension to the riders spec, ie: weight, ride style and road conditions.
i had mine set to my weight and ride style and normal CA roads, for me its perfect, and its like riding on air and yet if a lighter rider rides my bike they find it too hard and stiff.
i hope that answers your questions.