SparkEV said..
Need to replace old aluminum booms.

Of the 2 brands , which should I buy used ?

Chinook is 6 yrs old . Does it matter ?

toss up ?

TIA

HPL has been out of business for I'de guess at least 10 years. Yes it matters. OLD alloy booms will fail. either from fatigue or corrosion. So good call replacing with Carbon. I am biased but I would go the Chinook. Depending on the size the HPL may have a big round shape which is not ideal unless you are sailing big sails. 2014/15 Chinook will be modern shape & 1pc construction.