I too have been looking at the diesel market for a commute car & to save the miles on my ZS Mk.2. Will be averaging 350miles per week
Having considered various options, I have realised that the ZR secondhand market varies quite dramatically, in that there is quite a few on the market available. Whereas the ZS diesels tend to hold a better price, thus although you are dropping a few plates, in the long run, you are probably not losing financially & returning excellent mpg.
For my sins, I have be purchasing a Suzuki Vitara 20L Turbo Diesel!!!!