Super easy build. This is a must have output option if you are building an OLA5 or an EQP5. The Vintage Output and 2520 opamp turns the EQP5 into a desert island EQ for me. Fantastic for tracking, and in a stereo pair, magical on the two-buss.
I originally purchased the OLA5 without the Vintage output option. (What was I thinking??) The opto sounded very good without the VO, but once I had that built in, it changed the character of the opto for the better. I did a shootout between the OLA5 with VO and my JLM Audio LA500A optos. Similar output sections. The OLA5 was, slightly more forward, and silkier, at least in my initial tests.
Do yourself a favor and get the VO option if you're building either of these kits. You won't regret it.