at Sword Forum int., there's a post by Howard Clark (maker of the L6 Bainite) recommending the Cold Steel. I've heard other reliable people who got their cold steel warrior series say that thing can take some serious abuse, where a PPK would bend/chip/fail. Now mind you, a katana isn't made to withstand abuse- you shouldn't ever abuse one, but when you're just starting out cutting, then you're going to make some mistakes. Go with the cold steel- it's not indestructible, but it'll handle your beginner's mistakes with much more grace than alot of other swords. CS katanas are made to withstand punishment.
Some people are going to tell you that because they're not differentially tempered, they won't hold an edge. Totally untrue- they hold a quite decent edge and aren't to hard to hone with a ceramic stick if somewhere down the line you need to do that. Assuming you do alot of cutting. A sword shouldn't be extremly sharp anyway, the finer (thinner) the edge the more chance of damaging it, or causing it to bend/roll when you have a cut go wrong. Some people trash talk cold steel swords- maybe they got duds, I don't know. Maybe they didn't show enough respect their blade or know how to take care of it. That happens- but for the most part, I've heard very good things about CS katanas. Mind you, they're not eye candy- but I'd rather have a more reliable blade than eye candy anyway. Oh, and be careful if you're test cutting. It's way too easy to lose a foot when a cut goes bad and decides to reroute itself to your shoes. I'd advise against any playing around- be very, very, very careful if you do decide to test it out.
$!lv3r