Will you notice the difference between your series bass' electronics and those of a signature? Oh yes. You WILL notice the difference. However, people are unique in thier own ways, so will you like the sound better/not as much would be a valid question. Live in a big city? Go to a big store and play a signature bass. I like both, however, I prefer series electronics if I had to choose one over the other. Some one else will surely have a different taste in what they like.
Want a great bass at a great price - patience. Want one now, pay the price. I waited three years till my first Series II popped up on eBay and I scooped it up. Till then, I played a 20th Anniversary with signature electronics, and liked it very much. Time is money, after all. Have you got the time or have you got the money is a major deciding 'balance' in many decisions made in our lives.
BTW - What I say here has nothing to do with Stoney's bass. It is just general advice for a new member. Back to the focus of the tread, great bass Stoney!