I bought my own 2007 MCS in mid April, I am also an owner of the 03 Mini Cooper S. I have got to say the new one is definately a very good car like the old one! Drives the same but with more refinement(better seats, more comfortable, better mpg, more power/torque, etc).
The car is definately worth the price, mind you I have the exact options/colours as canadiandriver's review car! You can't compare the Mazdaspeed3 with this car, that's like comparing an Accord V6 to an BMW 323/328. The Accord will beat the BMW in a straight line and cost less, but we all know which is a better driver's car. The Mazdaspeed3 is more expension anyway (assuming you don't go nuts on the options with the MINI). [edit] my mistake, the MS3 is the same price. [/edit]
The new MINI is more BMW now, it's comfortable with the new leatherette seats and the new softer stock suspension(you can still opt for the sport suspension!). It's new engine has more HP and WAY more torque, where the old car lacked the torque for city driving, this new one shines in the lower part of the rpm. I am getting average of 28.5mpg with my car right now, with the 50L tank, I get about 550-600KMs!!!!!

To the person who said there's no JCW options, I can tell you there is so go check out the dealer! I believe it's about $5000 dollars, it will give you 200hp/210tq if I remember correctly. Not that you will need it anyway, I am running 17 inches Hankook Performance tires on my stock 2007 Mini Cooper S. In first and second gears, my tires are just spinning if I do WOT(wide open throttle) with my DSC off.

There are lots of cars that can compare with the Mini Cooper S, like the GTI, A3, Miata, etc. The MINI tho, is lovable, most people love the MINI's "cute" looks. No one will look at a GTI and say "omg it's a GTI", but they will all smile at the MINI. (no offence to the GTI, good car but too blend)

For those that are unsure about the new MINI, go test drive one and you'll see exactly why I love my car.