Katalox is a pleasant wood in a lot of ways. It is close-grained, turns well, and polishes up nicely. It has distinctive dark violet color and the grain can be very pretty.
The problem with katalox, however, is not that it tends to split, but that it "moves" a lot. That is, it swells and shrinks with temperature changes more than most other woods do. You need to be very careful where you store katalox pens. I left a nice katalox cigar pen in a car overnight during the winter once. In the morning, both barrels showed brass tube through gaps where the wood had split. The lower barrel actually broke in half lengthwise. I still have a bunch of katalox turning stock, but I rarely use it after that.
Regards,
Eric