I bought this to go with the purchase of an A-155 Sequencer and it gives far better control over that module and kind of completes its functionality. The only thing I wish it had, unless I haven't found it yet it would have been to be able to play the sequence for one bank and then the second on the A-155 from this module, so 4 stars for that. That said a sequential switch should sort that out and experimenting is all part of the Modular Synth experience.
This module does need to be connected up at the back to the A-155, but the instructions are pretty clear and provided you're methodical its easy enough.
Build quality is good as you would expect from Doepfer and the vintage black option will go with the rest of my modular setup perfectly. My only choice now is whether to get a second A-155 to go with this, or wait for the Behringer 962....or maybe both :-)