At times they look almost primitive compared to Busse knives,
They are supposed to, to some extent. He does a lot of japanese reproduction (at least in style, if not a specific direct historical representation) wich are inherently simple looking compared to a multi textured swag backed tactical knife. the core of japanese fighting blades and edge tools have been "edge, handle, handle wrap" and thats basically it. while the wrap and accoutrement's of the knife may be stylistically detailed, the blade itself is generally very very simple.
I think the Hartsfield (although simply looking) is the most effective weapon ever designed and brought to life!
one of his blades in particular fits that bill for me. heavy guard on both pommel and index finger, fine straight pointed tip, NO CHOIL, and the part of the edge that comes up the the gaurd is sharpened in a round fashion, lowering the chance of wedging. it's primary goal is the same as the Sheffield trench dagger. and I dare say that I would be more apt to choose phils design over the Sheffield's because I don't trust daggers (It's not safe for me to use one (because I will more likely injure myself then my opponent))
seeing his khukuri makes me sad

. Really my only beef with his work is the puuko grinds, wich (on any makers work) will turn me away every time.
But the puuko is a time honored blade grind, and if you like it, his work is top notch (from everything I've heard).
I can't help but think that you would get more responses to this over in the general discussion forum, or the knife testing and review forum (if your interested in how phils knives compare in use to busse's)