I'm watching this topic with interest. I've had a different strategy about the getting into the Centrotec system. Bought the PDC drill and with that the systainer with the attic lid.
I chose at that time to get the Centrotec bradpoint bit set 3mm-10mm , Stone bit set, and the bit set. Bought the HSS 3-10 and the Zobo drill set . additionally the countersink. Adding a few speciality bits and drivers as needed.
I think of upgrading the PDC drill systainer to the Sys combi 2 and moving the attic lid and PDC insert to it. In the bottom drawer I can keep the additional zobo and HSS bits. As well as the non centrotec bits.
My setup ends up being more complete as to the available Centrotec offerings, Haven't done the math but feel it's a fine comprehensive selection, with a great overview in a portable setup..