Smooth, swift and sophisticated, the new Jaguar XF saloon is going to make a big impression among potential buyers.Styled as a coupe but designed to deliver saloon practicality, the successor to the S-Type is less retro and more revolutionary for the brand.Not only is it brimming with the best technology but it packs in traditional Jaguar cues for comfort, composure and delivers dynamic appeal along with the emotional element.It carries over the familiar 2.7 diesel, 3.0V6 petrol and V8 4.2 and Supercharged V8 4.2 engines but they come only with the latest shift-by-wire six-speed automatic and paddle shifts on the column. Sophisticated electronics match the powertrain to the rear wheel drive traction control to give drivers a choice of grip and dynamics.I was most impressed by the ride quality of the Jaguar XF over a variety of surfaces in the South of France this week, from smooth motorway to coarse country roads with broken tarmac.Not only did it absorb all beneath but its handling was entirely assured and inspired confidence and playing with the DSC settings meant you could enjoy the responsiveness more than in the normal mode.There is a roomy boot and back seat for three and the front pair of seats have a very good adjustment range and excellent support but headroom in front may be tight for taller users with the low set header at the top of the windscreen.The only real noise with the cars I drove came from the big wheels and tyres, and very low level wind turbulence from the mirrors. There were no irritating noises from the powertrain, only pleasant exhaust notes.I drove both entry and top level versions of the Jaguar XF. The 207PS diesel is expected to be the best seller taking about 70% of sales and it's an excellent unit promising around 38mpg with 0-60mph in under 8 seconds and a maximum speed of 143mph.In the XF it pulls easily and strongly and so long as you utilise the automatic box to its potential you would never feel it lacked anything in performance terms for a medium sized four-door saloon.At the other end of the performance envelope you get a first class engine in the SV8, punching out 420BHP and giving 0-60mph time of just over five seconds with top speed limited to 155mph and a combined consumption of 22.4mpg.Depending on how it is used the SV8 is docile or downright quick, the changes can be soft or sporting and I thought the ride quality was even better in the range-topper than the entry level model.Not only will the new Jaguar XF give competitors a real run for their money, it will also appeal to XJ owners who want to downsize from the bigger saloon but not lose any refinement and who would appreciate a sportier package as well.