I have the 73-75 voice panel and some the R*S modules. The oscillators on the 73-75 have fewer modulation options and waveform outputs but you can shape them in various shapes using the filters, etc. Also as Jonny said, no 1/v but you can make it work with some tuning.
All that said, I think the 73-75 panel sounds fantastic. The filter is rich (I wish there were two of them), the VCAs are clean, the envelope generator is versatile, the ring modulator is fun. For the price and all you get, I love it. Definitely plan to buy the other two panels when they are released.