Well with a wider stance, your handling/cornering will be better. But be very carefull with wheel spacers cause they have been known to cuase problems with breakage ect. If you do go with them then dont go too wide.
does it affect speed or doing wheelies or what not, I am rather new to the dynamics of a racing quad, i have only ridden 4x4 my whole life. I am comfortable with my handling right now I dont rely on the bike to corner itself I swing it out with my body weight
the fronts are a bad idea if you ride hard. I kept breaking tierod ends and they made the steering extremly light and harder to control (bumpsteer).
The rears work fine I had no problems with them. They are a cheap alternative to an axel, but all they will do is confirm you like the ride with a wider axel and you should have saved up to buy a stronger lighter aftermarket one to begin with.
Not really a "good" alternative, but not all that worse an alternative either. Still nasty on bumpsteer, bent tie rods, etc and now you've exposed the inside of the front rotor. Not to mention you can't change from your sand tires to your trail tires and still keep the width unless you break beads or buy 2 sets of offset rims.