I assembled 4 of these for the studio where I’ve been working. Mike at Hairball has done an amazing job, totally revamping the kits since I built mine a couple years ago.
The PCB has been redesigned to span the depth of the chassis and the front panel controls are mounted to the PCB, cutting the amount of wiring down drastically. The attack and release controls are similarly mounted to a daughter board which connects at a right angle to the main board via JST headers.
A new active link circuit is available for pairing two units in stereo, connecting to the rear of the main board in the same manner. The power supply section has been re-designed as well to more closely match the original UREI models and the difference in tone is noticeable. Great product and a lot of fun to assemble.