Re: Paul Chen Practical Plus katana
I own a PPK. As others stated, it is an entry-level blade, just a step above the Practical Katana. My understanding is that the same blade is used on both models, the difference being that the Practical's tsuka is epoxied on (non-removable), whereas the PPK can be disassembled for tsuba or hilt upgrading. I've seen some folks do this, the results look good, but it's still an entry-level blade at heart. The blade comes differentially tempered, but not polished to bring out a hamon; instead, the hamon is acid-etched. The polish on the blade is decent, and it comes sharp, good for light cutting. In my opinion, the differential hardening left the spine softer than I like. My blade has cut soft targets well, but took a slight (1/2") bend on harder, more substantial targets (3" thick soaked newspaper rolls). It could make it through 2" rolls, but not thicker; however, my technique isn't that great. The fact that it bent, though, suggests to me that it might be OK for single tatami mats, but I wouldn't rely on it for intense tatami practice. I was able to bend it back to straight, it glides back into the saya, but I do intend to get a beefier blade in the future. This may not be a popular model, but the Cold Steel Warrior katana can be had for almost double the PPK, and is through-tempered (it springs, doesn't take a set when bent) without a hamon. Other differentially-hardened models in the Cold Steel price range would be a Last Legend Mark II or the Generation 2.
Hope this helps,