Okay, tried the HIDs out for the first time driving home from work tonight. They are installed on the high-beam side.
Wow, what a flood of light. They seem literally ten times brighter than my halogen low beams - when I switched from high to low beam when meeting oncoming traffic, it felt like turning off a spotlight and turning on a flashlight. They function just like the halogens did, only the light output is tremendous.
The quality of the kit seems first rate. Everything is black and unlabeled which makes for a very nice stock-looking installation under the hood. If I raised my hood it would take a sharp-eyed NSX owner to notice them - a non-NSX owner would just conclude that everything under there was stock. There are numerous aspects of this kit to recommend it, not the least of which is the extended dust caps and ballast mounting bolts. I also like WhiteNSXs choice of mounting location for the ballasts - nice and secure under the hood atop the fusebox mounting points on the inside fender humps. The kit is a snap to install and is truly plug-and-play. I think this is an excellent, high-quality HID kit and would highly recommend it.
Hot Info Regarding Temperature (color) Selection - The 4300k HID kit really is the default best choice - my only regret so far is that I maybe should have ordered the 4300k kit. The 6000k kit produces a flood of pale, almost ghostly light that is best described as being "teal" or "aqua", meaning a greenish-blue hue (not bright blue or deep blue). I have seen the the 6000k kits described variously as as being "diamond white", "diamond blue", or maybe "arctic white". But to my perception, on the light scale [ROY G BIV] they seem to fall somewhere about late "G" to early "B", ie, greenish-blue. The light reminds me of looking at headlights behind me in an automatic-dimming rear view mirror. I intend to order another 6000k set for the low beams 1) to match, and 2) because the difference between the HIDS versus the halogens is extreme so I need to eliminate the halogens, but I think the "diamond white", "diamond blue", or "arctic white" labels are misleading.
I really can't imagine choosing a temperature above 6000k. The 8000k would be very blue and they just get purpler from there on up...