I agree 100 %. The stock air cleaner flows very well up to 5200 RPM which is about the top end rpm range of the cam. As soon as a high flow air intake starts to show its benefit by inducting more air the cams need for air tapers off so it's a moot point. Install a nice set of mufflers and ride.
I do not disagree with the need for a tuner starting at stage 2 but for stage 1 the HD download is a perfect match. The vin specific ECM download increases the rev limit point to 6200 which is a moot point because of the cam limitations, but more importantly it loads a new timing map while keeping the correct AFR. This gives the bike a bit more snap and I believe it will run a bit cooler also. I know plenty of folks that have a Stage 1 with high flow SE type intake and just have the HD download and are plenty happy, myself included. When I'm riding with folks that have both download and tuner there seems to be very little performance advantage either way!
Now, if you plan to change head pipes, cams, etcetera, then check out a tuner.
BTW. Not trying to step on any toes here. Just that for some folks who know for sure that there are no future mods past the Stage 1 AND don't want to piss around with a tuner for any number of reasons can benefit from the HD download.