A discussion of O1 and A2 started in the Tormek portion of this forum. Use of the word "and" rather than "or" in the title was intentional. I believe both have places for woodworkers. The O1/A2 debate reminds me of the high speed steel/carbide debate for saw blades and router bits. The carbide side wins hands down for longevity, but the high speed steel carries the day for keenness.
Lie-Nielsen makes bevel chisels in both O1 and A2, A2 being the "standard" chisel. They grind their chisels to a 30 degree bevel, and suggests a 35 degree micro bevel. These chisels seem designed to be struck with a mallet, as in dovetail making.
They also make longer interchangeable handles for the chisels to be used in paring functions.
Who says hand tools are "simple" tools?
Ken