I currently have an '05 4x4 1.2 which, as others have said, is the old 60bhp engine. It is a smooth quiet car but the engine is frankly rather gutless and it would struggle to pull the skin off of a rice pudding. This did not bother me as I use the car almost exclusively for suburban driving, which the gearing suits well, and the low speed smoothness is appreciated. The odd longer trips I have done on motorways etc have been fine as long as you accept that acceleration at 60-70mph is limited, to say the least and drive accordingly. I actually enjoy this facet of the drive experience, as I like the laid back relaxing style of the Panda, and when I want to go fast, I drive my other car, which is blessed with nearly 500 horsepower.
However, like the poster above I am about to change the car for the new model, also in 4x4 trim. I drove both the TA and the Multijet. I drove both cars back to back for over two hours on a wide variety of roads, by the way. My findings were the complete opposite of the previous correspondent. The TA makes a fantastic noise but that is about it. It felt over fussy compared to my laid back 1.2, and always seemd to be in the wrong gear. It was of course much more powerful in real terms, but the engine and car seemed unsuited to me - it may work better in the ordinary Panda chassis, and I know it does in the 500 as I have driven a few.
By contrast the MJ was perfect. This is one of the most refined small diesels in the marketplace anyway, and the tidal wave of low speed torque completely suits the 4x4 character. It also means a lot less gear changing, and I suspect in my mainly urban usage, its fuel consumption should also be rather better than the TA. Okay it doesn't sound as nice, but in every other dimension, for me, it outpointed the TA in this set up. Like I said, in a regular 2WD Panda chassis, it might be different.
So, as you may have guessed, I plumped for the Multijet. Anyway, I pick up the new car on Monday so the proof will be after living with it for a while, but for now at least, I am (very) happy with my choice.