Here is my recommendations to you

Keep your current setup

Keep your ZR3 but replace your RD with the V1

I would stay away from the 9500i if I were you. The 9500i is built on the same platform as your X50 so the only added thing you would be getting is GPS. On the other hand if you can afford it the 9500CI it will have the same sensitivity as the STI-R and the STI-R has been out overseas for a while now and my sources tell me its sensitivity is as good and even better on some bands than the V1!