But the Infiniti's acceleration edge isn't just statistical. Its rapid forward thrust could be felt as soon as my right foot connected to its drive-by-wire throttle pedal. Take off is immediate, followed by the 5-speed automatic transmission's smooth but positive shifts, right up to 6,600 rpm - the redline for both V6 and V8 engines. Toggling the gear lever to the right puts it in manual mode, allowing a most satisfying level of driver input. Unlike most sequentially shifting automatics, the Infiniti unit only shifts when told to - most others, including that in BMW's X5, shift automatically when nearing redline effectively defeating the purpose of 'manual' operation. I found myself using the manual mode continually, something I rarely do in competitive models.

The shifter was especially appreciated when Phoenix, Arizona's flat, grid-like roads began to curve on the way up to South Mountain Park's lofty summit. The roadway is narrow, twisting and undulating, a perfect stage to work a little front-midship (FM) Infiniti magic - incidentally the FX shares its rigid platform with the best in class G35 sedan and coupe. One hairpin corner after another, the FX45's standard 20-inch rims (the FX35 gets standard 18s and optional 20s) deliver flat, predictable handling like no other SUV I've ever tested, aided by a wonderfully sorted Vehicle Dynamic Control (VDC) and Traction Control System (TCS) that keeps the rear end perfectly in check without spoiling the party. Electronic systems continue through to the brakes of course, where 4-wheel discs are assisted by a sophisticated anti-lock system that includes electronic brake force distribution and brake assist, capable of pulling the SUV down from lightning speeds to immobility in seconds while keeping complete composure all the way to full stop.