Oprod spring guide before and after groups?

[ipscgraz]

Anybody have any opinion on the round stainless spring guide that Marstar used to sell?

 

[AKS403]

I've replaced my op rod and spring with the CanAm fluted op rod. The spring has also been swapped out for a spring I bought from Hungry. As well as shims, again from Hungry. I have yet to get out and shoot, but the action seems also smoother since swapping the said parts.