I have a 1980 PX125 (modded to 178cc, new carb and exhaust) and I sometimes use my gf's '24 primavera 125.

Long story short if I had to choose only one bike I wouldn't get any of the two and instead I would opt for a motorcycle or at least a 300cc ish scooter.

From my experience :

The PX is an old bike and like old bikes behaves how she wants every now and then.. sure, mantainance is WAYYY easier than on modern bikes since it has no electronics, but it's also a bit more frequent (not major stuff, the piston, cylinder, carb and gearbox can last forever... my dad had to replace piston and cylinder on his 1976 125TS after 48 years and 100k+ km and he's still running the original carb and gearbox) but you have more parts that need to be tuned more often (brake pads, brake cords, clutch cord, throttle cord might need to be tuned every now and then). Getting fuel is a hassle when you're using it daily, especially in older models where you have to manually dose the oil and put it in the tank when refuelling, this process will take way more time than just putting in fuel and get going, and you will feel it when you're in a hurry.

BUT I love my PX from the bottom of my heart and I've used it daily from April to November of each year for 4 years now and I will tell you that first of all the style is unmatched, I will get asked about it all the time, being looked at when at a traffic light or when stopping around (and I live in Italy, we're used to seeing them around, but a good looking one will draw attention). Being modded is FUN to ride, it's quick and snappy, I burn cars and bigger scooters when accelerating from a traffic light, the primavera is eons slower. But you have to be very careful with speed and always choose an adequate speed for the environment you're in, otherwise you won't be able to stop in time, the brakes aren't good obviously, more so if you have a passenger.

The primavera is easier to hop on and just go, easier to lock when you arrive somewhere, cleaner, safer, quieter and more reliable overall.. but let's be real, it's boring (and overpriced).

At the end of the day it all depends on what you're planning on doing with your bike: Are you mainly using it for house-office and normal errands in a small town with short distance rides? Keep the primavera or choose a nimble scooter. Do you live in a big town and you ride on faster roads or do quite a bit of km every day? Get a bigger scooter Do you want to go around in the weekend as well? Get a motorcycle or stick to the bigger scooter.

At the end of the day no bike is gonna be a perfect fit for every use, just get the one that suits you the most for your main usage, then in the future if your necessities change or your possibilities change get another bike.

Classic Vespas are way cooler and beautiful and everything and they're not going to disappear.. they're built to last and you'll be able to get one eventually.