The TK-1 is a good looking design but...my big infatuation is with the NL-3.
personally, i'm lusting after a TK-5/6, but will be "settling" for a VG-10 WM1 (i've been saving up for an S1 and a WM1 for a while now, every time i get the cash, something happens which costs me $$ and i have to put the knife purchase back, again. i have other blades i can use in the interim).
the Northern Lights series are definatly lovely looking knives, however from what i can gather they are essentially the same as the others in the fallkniven lineup, but with a stacked leather handle at some substantial premium on the cost. i'll grant you the NL series is a full convex grind and lacks the bevel in the A1/S1/F1 series, how much this would effect performace is debatable. i'm on the "minimal difference" side of the argument.
as i see it:
NL1 Thor = No Other FK Equivalent
NL2 Odin = A2
NL3 Njord = A1
NL4 Frej = S1
NL5 Idun = F1
if the NL series were made in 3G steel rather than Fallkniven's standard Laminated VG-10, i could understand the additional cost and would probably buy them on the basis of the steel used.
as it stands, it seems like a lot of $$$ just for a stacked leather handle.
that said: if i was rich enough, i'd buy a full set of NLs in a heartbeat.