My 125 cc experience
Amigo I am Mexican and live in Mexico so here is what I lived with a 125
In 2004 I bought my first bike a 125 cc honda bros, and it was for learning to ride, but I just had too much love and fun with it so I keep it for 10,000 km until some one crash into me. I live in Baja so I did a couple of dirt single track days (very slow since I was new to bikes and dirt) some hwy in Mexico in both the toll and free road (two lane and much slower road) I went to school (I am a teacher) and even went to the USA on it and did 2 miles of interstate (I-5) and was scare to death! so I went back to city streets.
70-75 mpg or like 32 km/liter
cruising speed 90-100 km/hr top speed 115 km/hr
seat height was around 30" so for a beginner was great.
some good tires available (19 front and 17 rear)
range on the 3.2 gallon tank close to 200 miles
carb (for better or worse)
light and could get blow away on hwys
speed was not enough for the US (ok for Mexico)
if had a 35 watt headlight that I never change...
It was capable of carrying a lot of stuff since it had a way of tieing stuff to the back so you could easily have your camping gear plus some stuff and the gas tank was metal so a magnetic tank bag was optional
Would I buy a 125 cc again? YES! for touring? Only for Latin America given my time frames. for the US I would buy the 150 cc version of the same bike...or the 250 just to be safer.
If I was in Europe I would go 125 cc all the way, I remember the expensive cost from there (I lived in Czech Rep. back in 1995)
My 2 cents
KLR 650 my one and only!!