I use my '02 EX250 as a commuter. Approximately 40 miles round trip daily, mostly highway with a little mix of city.
I also have the SW Motech Rack w/ a 36L Givi Monokey box.
For reference, I've had the rack on the bike for approximately 12k miles, and rode 8k of that this past summer on a 4 week cross country trip. Has been rock solid with no issues whatsoever. Fits two helmets, or a backpack and stuff heaped on.
Overall, it has been a great bike. Good mileage, enough get up and go for commuting, cheaper tires and chain/sprocket wear, cheap insurance etc.
You can go two up with that setup, but it's going to be a little cramped, and not the fastest thing in the world. You *could* track it, too. I am running 17" EX500 wheels on mine with radials (fork and swingarm swaps), and good track tires are available if you do that. Even if you don't, Sport Demons and BT45s aren't that bad, either.
Weather protection isn't the best. A bigger bike will certainly be better in cooler weather. As you're in Ohio (Go Tribe
), I'll assume this is a 'better' weather commuter?
The Ninja WILL work. But plenty of other bikes will work too, with various disadvantages and advantages. You'll have to judge that for yourself...