Just an observation after having been away from Hyperborea for a few years. So I skipped the most recent adventures, but we had played everything up through Sea-Wolf's Daughter until the campaign ended with a near TPK (one PC survived only to later sacrifice himself in Tegel Manor). I recently grabbed Vanishing Isles of the Summer King, Thousand Eyes of Thaumagorga, and Oblation Slab of the Hepatomancer and I'm thoroughly enjoying my read-throughs. Good adventures, tied to the setting, but offering a fair amount of choice and DM freedom. Excellent presentation and artwork. Not too minimalist like OSE, but not too verbose, like DCC. Quite dangerous but survivable. And a free bookmark with every title ain't too shabby either.
On a related note, my homebrew mashup of Swords & Wizardry, Hyperborea, and Adventures Dark & Deep is coming together nicely. I'm updating my gazetteer now, changing a few things and cleaning up inconsistencies from earlier versions. Also actually typing it this time rather than writing it out by hand, so I can more easily make changes in the future. The fact that I had Glynn Seal do my maps is sweet too, since Hyperborea is bolted on as my North Pole.