16's?
I bought a pair of Harkin 16's many years ago as cabintop halyard winches for my Hunter 28.5. They are adequate for halyards, but I wouldn't recomend that size for taking someone up the mast. However the few ties I've done it, I take my halyard around the inside of the cabintop winch (as a turning block) and down to a primary and use a 10" winch handle on the primary. The angle isn't great but the larger OEM size 23 Maxwell two speed winches do a better job.That said, upgrading from Harken 16's to Lewmar 30's is twice the cost and the 16's are fine for the last couple feet of halyard or cranking in a reef.If you were also going to run a spinnaker and use the cabintop winches with turning blocks out on the rail (J24 style) it might be worth it to get Lewmar 30's.