I have used only 2 nakiris so far - Kanehiro 165 AS (a loaner from a friend) and a Toyama 180. Both are great. The AS is a great steel for a nakiri (holds up well to the 'chopping abuse'), the Toyama is more up my alley with slightly bigger size and higher weight. I shall get a Moritaka 180 AS in about a month if everything goes well - I do not really need it, but a friend wil be going directly to Moritaka, so he will pick up one for me.
I am still getting to know the Toyama, but I like it a lot. Very even grind (no low spots). After some experimenting I am getting a great finish on the cladding with a fine rust eraser from JKI - I can easily blend it with stone finish (up to Uchigumori) closer to the cutting edge.
I was VERY tempted by the Ikeda from Bernal, but the price was more than I was ready to pay (in particular after shipping and taxes). I would have got it (180mm, blue #1, damascus cladding) if the budget were not limited. It looks fantastic.
And of course you will hear a lot about 180 Watanabe - it seems that those are really good. I nearly got one myself, but could just not resist the Toyama.