I've owned an Escort 8500, V1, and now a 9500ix. The 8500 was very solid overall, other than weak Ka band performance, it was a life-saver years ago, when a lot of LEO's used X band in NJ. The V1 was amazing, however driving in semi-urban areas was terrible with the falses, and driving up the i95 corridor in CT rendered this RD useless. Was amazing when I was outside of the Metro area with less falses.
The 9500ix, although I just got this one a week ago, is turning into my favorite. Although I take a bit of a hit in overall range and the arrows were useful, the ability to find redlight cameras with GPS and have it "learn" your commonly traveled routes made it a MUCH easier detector to live with.