I ordered two Ixion pens from the Namisu kickstarter. I received the all titanium version (including nib) last week, and an anodized aluminum one arrived today. EF nibs on both.
Both of the nibs required a little smoothing, but I always tune new pens, so this wasn't anything unusual. The tines on both were slightly out of alignment, but easily fixed. And the cap threads on the all-titanium pen were a little scratchy at first, but after working with it for a bit, they have smoothed out nicely. The EF titanium nib writes a beautiful, wet line. The steel EF is super wet and a little wider (I'd consider it a Fine), but it's a nice consistent writer.
I'm quite happy with both of them. They're fairly large, a bit weighty (48g for titanium and 42g for aluminum), and comfortable. If you expect the pen to be perfect out of the box without any adjustment, you may be disappointed. If you're like me and always make adjustments anyway, you'll be happy. Build quality is great and they look very sharp. The comparison to a Kaweco Sport is a good one. Very similar in style, but larger.
I like the diameter of the pen, the length (I rarely post) and the straight section. These three things make them great for me, and I've written for a couple of long stretches with the titanium one and it was comfortable and not tiring, even though it's fairly heavy.
I'd buy another pen from them without hesitation.