Every thing most of you have said, makes sense. I will probably, when the time comes, trade in for the Ninja 650. So far, my ER-6N has been perfect for me in all situations. City, Freeway and Twisties. Not once did I ever say to my self, I wish I had more power. Only on few occasions I wish I had a screen, because my face shield is trying to be one with the back of my head. But that's only during some of the group rides. Very uncomfortable.
Modest Paint Job / Blue Reflective Wheel Stripes / T-Rex Frame Sliders / MotoWerk Flatfoot / MotoWerk Lowering Kit / MotoCircle Swing Arm Spool Sliders in Blue / Evotech Grill Guard / Blue Levers / Renthal Street Fighter Bars / Driven Gripps.
Just added sport bars to my new 650 and they def help in the twisties.
I'd say stick with the 650 and add the sport bars (190.00 online).
I still own a cbr 250r also and with the new sport bars in the 650 I have just as much fun in the twisties, but get to keep good acceleration coming out of the corner.
The 300 has less weight but the ride height is about the same on the both the 300 and the ER-6n. You might try different windshields. I was getting pounded by the wind above 60 mph and went to a taller and narrower windshield by powerbronze in UK, it made all the difference. Gas mileage will be better with the 300, but you will have less power. You will be running at higher rpm on a 300 while just put putting along on a ER-6n. If you hit a few gravel roads the 300 would be better.
It'd be interesting to see which screen are the most effective. I know highway riding was a bit of an adjustment from the faired 250r to the naked ER-6N. Power's great... but the wind beats on you. The Givi screen I have helped quite a bit, but I still get more wind than I did on the 250R.
Most of my riding is below 60 MPH, and I prefer the breeze, honestly. But I rode about 60 miles on the highway (70-80 mph) with a passenger this weekend, and while I love my ER, it's not the best highway cruiser out there, not by a long shot!
2008 Passion Red Ninja 250 - Sold!
2009 Plasti-dip black ER-6N - Sold!