Effect of weight on maneuverability/safety?

Hello!

I'm buying a scooter, which I'm going to use the vast majority of the time for urban commuting (10/20 minute trips within a metropolis).

My first choice would have been a 125cc scooter, due to low consumption and (supposedly) maneuverability in the traffic.

However, the class of scooters I wanted to buy is moving towards larger engines. Therefore I have to choose between a 125cc and a 300cc. The dimensions are mostly the same, however, there's approximately a 60kg difference (around 160 vs 220).

What difference does the weight makes, in general, in terms of safety (e.g. longer brake distance on wet roads, or difficult situations in general) and maneuverability (e.g. ease of move in the traffic)?

Thanks!