The issues are that whatever those ipac buttons 1 and 2 are mapped to (left shift, ctrl or alt) have some windows features like 'select all' or something like that, so if you use the same buttons for the ipac and optipac and click a lot on a lot of different things in windows, you build up a bunch of stuff selected, and then when you double click to execute, you launch everything. It's not a horrible thing but it can be a pain at times. For me it's worth it because I wanted a super clean and non cluttered control panel and I was willing to make some sacrifices for it (some days I really want that spinner knob but boy do I not want to look at it nor lose the real estate).