I would say, it depends. I have seen 200TT pilots who shouldn't even have been given a ppl and, I've seen 200TT pilots who are competent with a pressurised twin.
If you are happy in the Arrow, the Saratoga isn't that much of a leap really. You will have W&B differences to adjust too as well as the increased performance but other than that, they are very similar.
I've had an Arrow 1, Arrow IV, T Tail Turbo Lance and a Saratoga SP. All very similar, although the Turbo T Tail Lance was a different operating regime.
Insurance. I would say that the insurance company will ask for 10-20 hours on type.Dual. By that time, with your IR/R you will be approaching near to 250TT so definitely insurable. The Saratoga SP is a nice capable machine. Enjoy.