[g-land]

This question is specific to the Easton SLX Fork, once the fork is properly installed is it necessary to continue to use the compression plug or would removing it for a little weight savings be the end of the world? Anyone out there try this?

 

[SDizzle]

Will your steerer tube fill up with water? My Ritchey WCS fork isn't open on the other end. Something to think about...

 

[gizzard]

Not worth it

The plug/bung serves two primary functions: to assist clamping the stem down on the steerer/headset assembly before the stem has been tightened in position; and to provide internal buttressing (support) for the steerer tube where the stem clamps onto it.
It is extremely unlikely that your stem will disengage from your steerer (if it has been correctly tightened) without the bung/plug being installed, but it is possible for the steerer tube to crack and maybe fail completely if the plug is removed.
I would seriously discourage removing it and forget about the potential weight saving.

 

[gremelm]

This question is specific to the Easton SLX Fork, once the fork is properly installed is it necessary to continue to use the compression plug or would removing it for a little weight savings be the end of the world? Anyone out there try this?

Didn't your SLX come with the "bear trap" adjuster? Yes, as some have already mentioned, the expander does serve a purpose but it's really unnecessary if you have the adjuster and installed the stem and fork correctly...ie, proper bolt torque. I've been riding my SLX equiped bike for +4 months with the adjuster with no expander and it's fine.

Also, make sure you apply some LocTite to the adjuster bolt and stem bolts. But if weight savings isn't a priority, then go ahead and use the expander minus the adjuster.