Any feedback on the pros/cons of the 125 are appreciated!
At the outset, if you are not heavy set, is truthful about what you have said about your needs, the CBR125R could do well for you, and thus, I would recommend that you test ride it.
The positives for the 125R are many.
Stock front brakes are excellent if you know how to keep them clean. Once the fuel system/injectors are cleaned, the power is actually decent enough. The dealer's test bike and my bike when brand new off the showroom floor were not usable. I rode the bicycles routes at first because I felt that I couldn't ride on the main roads without getting run over. Once sorted out, power was O.K. (The other bike I ride is a Bandit 1250S).
The throttle modulation is very good. There are no issues with on-off throttle jerkiness nor driveline lash. The bike is dead reliable. The battery and charging system never gave me a problem nor anything else besides the front brake lever pivot, which binds if you ride in the rain. Initially, I thought that it was due to the caliper sliding pins. A squirt of WD-40 did the trick. As to valve lash inspection, there are only two valves. An oil filter change requires no oil filter, and only one liter of motor oil. An oil change is really easy to do. Chain maintenance is as easy as it gets since I can prop up the rear wheel up with short piece of 2x4 and a very light tug. I lubricate the chain very frequently and the chain life has been excellent.
The 125R is a motorcycle that is very easy to find a parking spot for; and it is very easy to maneuver it into a parking spot.
Even when the front end washed out, I still managed to stay upright. If you ride a downhill bicycle, the 125R is not that far off. The wet weight of the 125R is around 280 lbs. whereas the Ninja 250R is around 380 lbs. Compared to most motorcycles out there, the steering is extremely quick, and the bike is very agile. However, I still pushed the stanchions up the triple clamps by about an inch to quicken the steering and improve agility. My 125R is really easy to ride. It rides like a downhill mountain bike, and to me, that is a good thing. With that kind of agility, riding in the city can be very fun. Having said that, when I ride out east on Hwy 1 towards Abbotsford or south on Hwy 99 towards the border, I can ride with the flow of traffic for the most part and make passes (note that the flow of traffic is not at the speed limit and the speed limits increase further out; strong head winds or ascending a hill will slow me down a bit, my 125R is not stock, and we are still talking about a 125cc 4-stroke). The bike is stable. I never have experienced stability problem with this bike. Although, the first time in a wind storm on top of a bridge, I was blown around. But after I figure out how to ride it, I never had that problem again. It turned out the bike was stable, but I was destabilizing it. I have ridden the 125R in wind storms while crossing bridges, or cruising on freeways without any issues. Without saying, wind buffeting from a semi beside you doesn't have to be a problem either. But beware, if you don't ride it correctly, the 125R can be blown across half a lane in a blink of an eye in a wind storm at higher road speeds.
On unfamiliar roads, sometimes one may misjudge cornering speed, or wasn't setup for it, the 125R can give you a second chance, instead of just forcing you to go wide. The chassis is very forgiving. It is still possible to make "steering" corrections, and apply firm braking in mid corner to save it. The 125R doesn't have an affinity for "standing up". The bike doesn't go wide when I brake in mid corners.
Great gas mileage. And you get to use the full rpm range on every ride.
There are some negatives. The 125R has low cost dampers, and therefore, low performing damping performance. This isn't a real problem for me since I ride in the city and is rarely affected. Shifting is not smooth nor positive after some use. Engine vibration is busy over 8500 rpm and smooths outs near redline. But the hands nor wrists really get numb like from some inline-4's. Rear view sucks; can only see elbows unless tucking them in. No clock (I know, but I like a factory clock). Every horsepower is valuable so you can't afford to squander it. At highway speeds to keep up with traffic, I keep my head low.
For myself, the more I ride it, the more I like it. And this year will be my third year on it.