I am positive that I have a small leak in the vacuum hose that runs from the pcv valve to the oil resevoir...

How important is this for performance? My car has seemed sluggish forever, and I wonder if I have finally found out the problem...

Any expertise to share would be appreciated

 

All vacuum hoses are very important or else they wouldn't be there. A vacuum leak can dramtically decrease performance, get that hose replaced.