Are these 400s full on sport bikes like 600s, or more semisport like the 250?

Me too. Bike looks much better in person.

Full on, just like the 250 strokes they replaced

I like it

I like it as well. I've always been a fan of 250's. Something about flicking around at high revs and NOT getting a performance award from the local PD is appealing.

looks.... eh.
i think the baby ninja looks better.

but i do think it's great for new riders to have more options.
maybe more manufacturers will follow suit.

My Ninja 250 does 110...115 if you lay on the tank.

It has more than enough scoot available to upgrade you from "Do you know why I pulled you over?" right to "Good afternoon sir, you're under arrest, please step off the motorcycle".

Yamaha might, suzuki is too busy furiously treading water to consider new bike markets

Most of my small bike experience has been 40 and 50 mph in 20 and 30 mph corners so no worries there...
I have track time on FZR400s, TZ250s, SV650s and they will teach you more than a 600 or 1000 will. Not to say thelearning curve is safe and pain free.
Think these small cc 4 strokes are key to building a newbies confidence tho, at less refined and stable platforms that supersport they eventually upgrade to will feel like a jet fighter, but they will be more relaxed and comfy on it.

Too bad a single-cylinder can't rev.

What Dave said. They are deadly serious machines, and in the right hands are faster than damn near anything you'll find on a tight twisty road. They really scream up top, but you have to ride them very much like a 2-stroke and keep them on the boil at all times. They are challenging to ride really fast, but hugely rewarding when you get it right.