This is perhaps my first post in this forum. I'm usually over in the CRK discussions commenting on my all time favorite knives, but I've got to say that if the Sebenza didn't exist, the big dent in my wallet would be a result of products coming from Tualatin.
I agree with flarp on most points. I've been very impressed with these knives -- so much so, that I've acquired four of the 0550s (two gen 1s, two gen 2s), and three of the 0560s. I like both knives, for different reasons.
0560: Kai invests an incredible amount of materials and processing into these knives. The raw piece of Ti they start with is a substantial piece (imagine a box enveloping the lock-side scale -- that's a huge, expensive piece of Ti). All of that machining that they do to sculpt the lock side and mill out the inside pockets comes at a high cost. Of course, the El Max is expensive. Lots of little parts to contend with during manufacturing. I don't know how they do it for the price that they do, and here in the USA, no less. I'm impressed. The knife works well, and it carries easier than any other comparable folder this size because of all the weight reduction tactics employed. Of course, I like how the knife looks, feels, and works, but half of the reason I carry it is to show my engineering buddies, "Look! American ingenuity and manufacturing prowess is alive and well!"
0550: It doesn't have all of the investment into it like the 0560 has, but it's a nice piece of engineering none-the-less. The 0550 feels better in my hand than the 0560 due to the 0550's particular ergonomics and smoother surfaces (the 0560 is a bit abrasive for prolonged non-gloved use). The 0550 is more efficient with blade-length than the 0560. You can see it in flarp's photos. Folded, the 0550 is significantly shorter than the 0560, yet the 0550's actual blade length is just a couple mm shorter than the 0560's. As a result, I don't give up much blade carrying the noticeably shorter 0550. That's a big plus, IMHO. Today, I prefer the 0550's traditional washer bearings because they are so tried and true (and the 0550's implementation is
very smooth). When I experience KVT after a lot of use, all gunked up like I'm sure mine will get some day, I'll have a more informed opinion of KVT. The 0550 is more dense than the 0560 due to the fact that it lacks the internal pocket milling that Kai puts into the 0560. I wish they would apply that weight-reduction tactic to the 0550. If they did, for me there would be no contest between the two.
0550 Gen 1 vs. Gen 2: Because the DPC clip has a slot in it for screw access, it is not as stiff as the Gen 1 clip. This makes the Gen 2 clip a bit more fragile (easier to get bent out of adjustment) and not seem as secure as the very substantial Gen 1 clip. I don't care much about DPC, so I use the Gen 1.
I find that the 0550 gen 1 is in my pocket about 50% more days than the 0560. (On those days, however, the 0560 is in my briefcase, because a knife discussion invariably comes up in the office, and out come both knives for show 'n' tell.)
The 0560 is indeed longer, but it is also narrower and a bit thinner than the 0550. I find the 0550 does feel like it fills my hand better when gripped tightly. I prefer deep pocket carry, so I went gen 2 on the 0550. The lockbar cutout on the gen 1 0550 is also on the inside, if you would rather have an all-flat surface for the Ti scale. I actually like the 0550 a bit better than the 0560, mainly due to its size. The feel of the 3D machined G10 and Ti scale, though, is really awesome (just like on the 0200 and 0300 models).
Some side-by-sides: