Normally I own only one ship. Currently this is a T9 which I use for heavy trading, but also for bounty hunting in USS (yes, really).
I also bought a Vulture today, because the empire offered me some unexpected ascension missions. I was just promoted to Count.
I had great fun doing combat in the Vulture. I might keep it. Not sure yet, because I also miss my Python. Personally I feel having all these ships floating around feels like wasted money to me. When I eventually become a multi billionaire (in ten years or so) this does not matter anymore, but currently I need the money for a fully upgraded Python.