One thing to remember about using the DA42 is that it has a much better first time pass rate for CPL and IR than more "traditional" aeroplanes. Here at The Flight Centre (Wolverhampton), we found a great improvement in first time IR pass rates when we replaced our Seneca with the DA42 - and we're not alone in finding that to be the case.
Using a G1000 DA40 for the non-complex parts of the CPL makes for a nice, smooth transition to the DA42. We also run diesel PA28s but have found that customers much prefer the DA40 to the Piper.