[Elecraft] K-3: Best filter for SSB Contesting?

[RLVZ at aol.com]

Hi Guys,
 
For SSB contesting: if your K-3 radio had the stock 2.7khz filter and you  
could only select one optional roofing filter for SSB contesting, would you  
select the 2.1khz or 1.8khz?  
 
I'm mainly a CW operator and have one blank remaining for either a 2.1khz  
or 1.8khz filter.
 
Thanks for your thoughts!
 
73,
Dick- K9OM