I really like my ebony handle from K&S. Really beefy in terms of weight but it makes the balance on my mazaki enjoyable. It's definitely got a slick texture but I've had much more slippery handles from other places. Overall the quality is quite nice in my opinion
I've never handled the ginsan version but I've read good things about it. In my limited experience with ginsan I've really enjoyed it's edge-taking abilities and I trust the word on the street that Tanaka treats it with respect.
Tanaka in blue 2 is incredible for the price, especially with that gorgeous brass capped handle it sports at Knives And Stones. Takes an aggressive edge with very little time on the stones, edge retention is excellent as well