I'll get out and ride my 250R this time of year when we have midday temps in the low to mid 40's F. I haven't found that it takes much longer to bring the engine up to operating temp... maybe a couple minutes more of slow cruising to see 3 bars on the coolant temp gauge, but that's about it. The beauty of liquid cooled engines is that they run at a consistent internal temp, regardless of the ambient air temp. Whereas air cooled engines can be a bit more finicky, particularly when it comes to very high ambient air temps, where peak power will start to drop off. And of course carbureted air cooled engines are effected by extreme low outside temps in that they can take much longer to warm up and begin to run right.
I suppose 'cold' is a matter of perspective depending on where one lives... here in northern New Mexico where I live, 40F - 45F is the typical high daytime temp this time of year, with early morning temps often in the single digits and low teens. For other, more northern states, 10F - 20F might be the best they can hope for a high daytime temp during the winter months. So yeah, 40F isn't exactly what most people think of as "super cold". In fact, virtually any gasoline powered internal combustion engine will run better, and create it's maximum power at lower ambient temps like 40F, than it will at say 80F and above. Colder intake air temps are where it's at when it comes to creating optimum power & performance.
From my earlier post in this thread:
... a quick 'double clutch' action on the lever will allow the gearbox to slip right into first gear. Some people will roll the bike a few inches while pushing down on the shift pedal, which also works. I find it easier to just pull the clutch lever a second time.
We've had a lot of new riders over on the CBR250.net site complain about this neutral to first gear shifting issue, thinking that there was something wrong with their particular bike, when it's actually a common idiosyncrasy for a lot of different motorcycles. My '12 CBR250R now has 15,000 miles on the odometer, and I've always had to double clutch in order to shift from neutral to first... it's just how it is.
No intention of criticizing, but I'm just curious why you went down in power from 600cc supersport bikes to the 300R? (I know of a lot of riders who own 600 SS bikes and who have also bought CBR250R's, but it's usually in addition to their 600's, not as a replacement bike.)
Interesting... most owners who have complained about the side stand on the CBR250R/300R have thought that it is
too long, and puts the bike in too much of an upright position. My 250R leans over on the side stand just about right when it's on the level floor of my garage. If I'm parking it somewhere that isn't very level, I have to allow for that in the way I park it. It's just common sense really.
Somewhat humorous story: I recall someone on the CBR250R forum a couple years ago complaining that their bike fell over when they parked the bike on the lawn in their front yard. Yeah, I know, hard to believe. Unfortunately for some people (far too many people actually), motorcycles don't come from the factory supplied with "common sense', just an Owner's Manual. Of course the O/M has to be taken out of it's plastic bag and actually read by the new owner. Surprising how often that doesn't seem to happen.

I also remember another new CBR250R owner who said "why should I bother looking something up in the O/M, when I can come on a forum ask the question". He got pissed off when another member (not me) replied that "it's a very good idea to sit down and read through the O/M to familiarize yourself with the bike". Some people...as I recall, his original post was asking what the recommended tire pressures were.
I do have to say that I find it just a bit odd that anyone would have a complaint about the cosmetic look of a motorcycle
after they've bought said bike, when there are obviously other choices of bikes to buy out there. And no one ever buys a car or bike not knowing what it looks like.
So why didn't you buy the Ninja 300 if that's what you really wanted in terms of an aggressive look?... not to mention that the Ninja 300 has significantly more horsepower and top end performance than the CBR300R.
Also a common complaint on the CBR250.net forums, mainly from young male new riders. Who cares what anyone else thinks or says about the bike you choose to ride?... tell 'em to piss off. If it happens to be an officer of higher rank than you, make sure you salute first before telling them to "piss off,
Sir." Don't forget the 'sir', they really get bent out of shape when you don't end your reply with 'sir'.
See my previous post regarding the gas cap. Most gas station fuel pumps i've seen have a flat surface on top of the pump to set the cap while you're pumping the gas.
As for some sort of a tether, if it did have one I could see all the complaints about how the gas cap is scratching the paint on the fuel tank.