Thanks guys. Seems like there is a great group of people on here; I appreciate the warm welcome. Meant to write a brief review and upload some pics earlier but we are in a huge push at work so I only recently got home. Phone camera is broken so I'll use the wife's and get some pictures later on. For now I'll write a brief review based on my initial experiences with the bike. My riding background: I've been riding a heavily modified '15 FZ-07 for the past two years that doesn't resemble the original bike; everything from the headlight, suspension, bars, grips, fueling, exhaust, chain/sprocket, and bodywork has been modified or upgraded. I've gotten accustomed to the low end grunt of the FZ, but it's also ready to sing it's heart out to 9k and pull the whole time. I'm very particular about how my bikes are set up and I do all of my own work; with that in mind, I plan on making a good number of modifications to the Ninja 400. I am in no means saying the 400 is in dire need of fixing, but there are several things I would like to tweak.
Fit and Finish
Especially given the price of the bike, I'm happy with the fit and finish all around. I have (or rather the wife has) the grey/black/gold model, and the fairing and plastics have high quality paint and look quite sharp in person. The analog tach looks great next to the LCD cluster and in general the whole instrument layout feels very high end. Main gripes would be the boxy swing arm; I feel it looks cheap and kind of distracts from the overall sporty aesthetic. The license plate mount/rear turn signals are pretty ugly as well, but that's the norm with new bikes these days and is easily fixed with a tail tidy.
Ergonomics
Seat height is extremely manageable unless you happen to be really short. My wife, who is 5' 5" finds the height to be perfect. The bike is narrow so it doesn't feel like your legs are straddling a cow. I can't say I'm too happy with the stock levers and throttle feel; I'll be swapping those out shortly. For smaller hands, the clutch pull is quite short and insanely easy to pull. I've never ridden a bike with such a light and short clutch pull. In terms of seating position, it is a mix between comfy and sporty, but not too sporty. You can definitely get down on the tank, but to do so properly you are going to need a new pair of rearsets.
Ride
I was pleased with the bike's suspension action on my initial ride. No jarring from high speed suspension events (bumps and pot holes) and no significant brake dive or squatting under acceleration (low speed suspension events). This surprised me since damping rod forks typically dive hard under braking, as was the case with my FZ until I swapped for cartridges. Given the price point of the bike I wasn't expecting much but I was pleasantly surprised. Brake feel was decent and I have a feeling will become a good bit better after some modifications. This bike is extraordinarily light and the low CG makes it easy to maneuver. I almost felt like I was riding a bicycle through the few turns I took on the way home from the dealer and I mean that in the best way possible. Seems like this machine has some great canyon carving potential, which is where most of my riding takes place. Power delivery was smooth, but I wasn't too happy with the throttle feel. That's an easy fix, as I suspect that the throttle cables are stretching and need to be tightened. My other complaint is just how quiet the 399 cc motor is. Granted, I didn't wind it up past 8k (and I have no plans of doing so until it is properly broken in), but it sounded like a sewing machine to me, and I wasn't even wearing ear plugs. My FZ is loud as **** and sounds like a straight piped V8 racing boat motor, so I'm probably a bit biased here. I think a good quality exhaust system (not just a slip on) and an ECU reflash could do wonders in improving the visceral feel of the bike, as well as getting some more oomph out of it. That being said, I haven't given the motor a fair shot yet, and I could feel its potential picking up as I reached the 8k RPM threshold. It seems like this bike will reward you for wringing its neck, just like a two stoke or a 600 cc class sport bike.
All in all, I'm quite happy with the Ninja 400, but I can't wait to start modifying it. Hope this helps anyone who is interested in purchasing this motorcycle. Like I said I'll upload some pics and probably a modification list at a later time. Given that this is the wife's bike I can't get too carried away. My intention is to set it up for her quite nicely while also pacifying my inner perfectionist when it's my turn to ride it. The good news is that while there are few direct fit parts available for the Ninja 400 at the moment, there are a good deal of universal and Ninja 300 parts that will fit and can be had now. I'm sure the aftermarket will be picking up steadily over the next few months as the bike sells.