The two cars share the same bluff-fronted nose, but the Paceman is 4cm lower, and its roof and tailgate are noticeably more raked, giving it a look reminiscent of the Range Rover Evoque Coupe.
Four engines will be offered: 121bhp Cooper and 181bhp Cooper S petrols, and 110bhp Cooper D and 141bhp Cooper SD diesels.
The S petrol and diesels are available with front- and four-wheel drive, whereas the entry-level petrol is front-wheel drive.
Mechanically, the Paceman is said to be almost identical to a Countryman on sports suspension, albeit slightly lower. The standard Countryman suspension set-up will be offered as a no-cost option.
The Paceman is lower than the Countryman, and its roof and tailgate are noticeably more raked
What's the 2013 Mini Paceman like to drive?
Our test car was a front-wheel drive Cooper S with the standard sports suspension, yet the ride didn't feel overly firm.
True, it became a bit fidgety over pockmarked roads, but it never crashed or thumped over bumps in the way the taller Countryman tends to.
This is surprising given the Paceman's supposedly firmer set-up, although we were driving the car in Spain and on the smallest wheels available; it remains to be seen how it will cope with the UK's more challenging surfaces and lower-profile tyres.
Come to a corner and the Paceman turns in quickly and without much roll considering its elevated, SUV-like stance. However, the light steering doesn't offer a lot of feedback, so it can be difficult to place the car exactly where you want it.
Also, while the Paceman handles reasonably in isolation, it's not as agile as the smaller Mini hatchback or conventional four-seat coupes, such as the VW Scirocco.
In other respects the Paceman Cooper S is much the same as the Countryman Cooper S; its 1.6-litre turbo engine feels a bit flat below 1500rpm, but delivers brisk acceleration beyond that.
Unfortunately, there's some engine resonance in the cabin at motorway cruising speeds and wind noise is also prominent.
What's the 2013 Mini Paceman like inside?
The Paceman's interior is virtually identical to the Countrymans up front, which means you get a retro dashboard that takes some time to learn because it puts style before ease of use.
The one slight improvement is that the electric window switches and the central locking control have been moved from the centre console to the doors.
You sit higher than you do in a Mini hatch and get a wide range of adjustment, but the seats aren't particularly supportive and the controls for adjusting the angle of the backrest are rather hard to reach.
Move to the back and you'll find a pair of individual bucket seats with Mini's aluminium accessory rail threading between them.
Getting into the rear is much easier than it is in the Mini hatch because there's a large gap to climb through. However, the front seats don't return to their original position after being slid out of the way, forcing you to reset your driving position.
Rear seat space is quite tight for six-footers, and the seat backs lie at a steep angle when you fold them forward to extend the modest boot.
While the cabin feels solidly constructed, there's too much hard plastic compared with a VW Scirocco, let alone premium hatchbacks such as the Audi A3.
Should I buy one?
Mini is aiming the Paceman at buyers who want the style and sportiness of the standard Mini hatch, but need more rear space.
The trouble is, it's neither as good to drive nor as refined as the hatch, and it will cost 940 more than the equivalent Countryman despite its lower door count.
This means a Cooper S like the one we drove will set you back 22,355. Unless you really like the looks, the similarly priced Audi A3 and VW Scirocco are better alternatives.
What Car? says