Re: Which Scope?
I can't comment on the Nikon or Kowa, however I searched, read, and asked around as much as I could about them. If around the $1000 mark is your target, I'm assuming that you're looking at the 60 - 66 mm Kowa, possibly the 82 mm Nikon fieldscope, and which Vortex...... Razor?
The Nikon and the Razor both have larger objectives than the Kowa. Simple matter of physics here - larger obj. allows in more light. In my research some said that the awesome ED glass of the Kowa really helps close the gap, but there is still something to be said for that larger obj. letting more light in.
What ever brand you go with, spend the coin on a scope with ED glass. IMHO, yes it's well worth it, especially when trying to resolve small details such as bullet holes.
I currently have the 20x60x85mm Razor and highly recommend it. It's right up there with the other alpha class scopes but doesn't command top alpha prices. Note it will come in over $1000, but if you shop around, not as much as you think. Vortex's guarantee and well known customer service also played a big part in my decision.
Would I like to have the 88mm Kowa? You bet, but for around $1000 more than the Razor I couldn't justify it.
At 100 yds, the razor is almost like standing right in front of your target. Have never wanted any more scope. At 300.... depends on the day and conditions, but this isn't the scopes fault.
Look through as many of your choices as you can, if that is an option. I wasn't able to do that myself, and took a leap of faith on the razor. Hind sight being 20/20, I still have no regrets on my purchase.
As far as calling vendors goes.... I called Scott @ Liberty Optics. I explained my wants, wishes and needs which sound pretty similar to what you are after. Scott carries all 3 brands that you mention, and after personally talking to him a number of times dealing with scopes, spotters, and tools I'll put it out there that he gave me his honest opinions, straight up. He laid out in plain talk the pros and cons of whatever it was that I was looking for info on. He answered my questions with no B/S and even more important, no sales pressure.
In June/July Vortex is supposed to be coming out with a Viper HD under $1000 that was reportedly well received at Shot show. Scott touched on this in his shot show blog.
If I were looking today, I'd call Vortex and talk to Sam or Scott and ask for the low down between the Razor and the Viper HD for what you want to do. Both are active on the forum here and are happy to talk to you when you pick up the phone.
Sorry couldn't be more help.
You might also check here -
http://opticsthoughts.com/index.php?option=com_content&view=section&id=3&Itemid=6
Ilya is much more knowledgable about optics than I'll ever be.