Well, it also takes me 6 seconds from tapping the OF button to first character on a new note, on an iPod Touch with auto-sync on. For comparison, it takes about 4 seconds to launch the Apple Notes app and start a fresh note page (an appropriate comparison, I think, because OF is giving you an independent action, not adding to a previous one), or 3 seconds if I wanted to just add on to the previous note. On the other hand, I can fill in most of the details of that action, including context and project if OF isn't syncing at the same time, and even record an audio note or take/choose a photo (or screen capture), and when I'm done, it's in my database. With some other program, I'll have to come back and process any or all notes into OmniFocus, and that's going to take more than a few seconds per note, and I have to remember to do it in a timely fashion. To me, that's a trade-off where using OF's quick entry button is a net win, but you may find it otherwise.
Ken did spend some time in this latest release cycle working on making quick entry available as early in the start-up process as possible, and during most of the sync process as well. I doubt that he would say that nothing more could be done, but I suspect most of the low-hanging fruit has been picked, and substantial improvements from here might be hard to come by. It would be interesting to hear what sort of start-up times to first characters entered you see with other applications.