I've got 4 KoAlohas with Tenor necks (Tenor, SuperConcert, Pineapple Sunday, Tenor Sceptre), and just one with a Concert Neck. I'd say it's just as comfortable, and just longer. Of course, the KoAloha necks are all hand shaped, which means that no two are the same. My superconcert probably has the thinnest (depth-wise) neck out of all of them, which I do not prefer. I prefer the more beefy neck on my Tenor, PS, and Sceptre. But even then, I can feel the slight differences in the taper among those necks. Another aspect is the neck finish. I sanded the finish on my Superconcert neck down to basically a satin or silk finish just to see how it'd feel. I like it better than before when it had quite a bit of finish on it. The finish on my PS, Tenor, and Sceptre necks feel thinner and I don't forsee sanding that finish off. Finally, the higher and fatter frets that KoAloha uses just makes the necks comfortable to play. I like them all, but they're all handmade, so they will be different.
Compared to the tenor necks on my Kanilea and Kamaka, I would honestly say that I prefer the KoAloha, at least based on the instruments that I own. Kanilea's UV finish sometimes gets sticky when my hand sweats on the back of the neck. Also, I find their neck a bit thinner than I like. HOWEVER, Aldrine's Kanilea has an awesome neck thickness and profile. I absolutly love that neck, and I think the KoAloha PS that I have gets pretty close to that shape and thickness. Kamaka also has a nice thick neck, and awesome body balance with the center of balance on their tenor right at the 12th fret. Another cool thing is that Kamaka's neck is a one piece construction. I really have no complaints against their neck, but the "feel" of my KoAloha tenor neck is just "better" to me.
It's hard to describe, and different people have different preferences. But I do like KoAloha's tenor neck. However, the best neck that I have ever played is still Aldrine's Kanilea. It was like magic to my hands...night and day difference between that neck and the neck on my K1-T. So important lesson there is that even though it's from the same maker, the necks can be different.
