Firstly, it's important to consider your own riding preferences and needs. If you have over 25 years of riding experience, you likely have a good understanding of what type of motorcycle suits your riding style and comfort level. Consider factors such as your preferred riding position, power and performance requirements, and the type of riding you'll be doing most frequently.
A 350cc motorcycle can be a great choice for many riders, offering a good balance between power and agility. It can be suitable for various types of riding, including occasional motorway use. While larger motorcycles may offer more power and potentially better long-distance comfort, they can also be heavier and less maneuverable, which may not be as important for your riding preferences.
Additionally, owning a 350cc motorcycle can have its advantages, such as lower purchase and insurance costs, as well as potentially better fuel efficiency. It may also be easier to handle in city traffic and for shorter rides.
Ultimately, the decision depends on your personal preferences and requirements. If you feel comfortable and confident with a 350cc motorcycle and it meets your needs for the majority of your riding, there's a good chance you won't regret your choice.
Remember, it's always a good idea to test ride different motorcycles and consult with experienced riders or motorcycle professionals to get their insights and advice before making a final decision.