Isn't the new Leon wider and lower than the old one? As has been stated hundreds of times in this thread already, there is new legislation/guidlines and whatever now for pedestrian safety and they are pretty much guiding designers as to how new cars look. Look at the 307, Mazda 3 etc etc, they all have the same shape due to this. Many many people now buy cars judged on how safe they are so this has to be taken into account by the manufacturers.
I do like the old Leon a lot, hell i bought one! However as has also been stated quite a lot, it IS looking dated now and the technology certainly is in comparison with some of the newer cars. Although the new Leon is quite different to the old one, i still like it a lot and one thing in its favour as i see it is that the base models now look quite intersting in comparison to the old model. Perhaps i see it as an Alfa without the concerns of reliablity/ build quality - it looks a bit different to the norm and certainly stands out compared to the Golf/A3 etc