Why not upload the pictures for everyone to see?

It is not unusual for the engine speed to be slow out of the box. You would need a tach to adjust or a shop could do it for you. Other things that you could experiment with would be to change the pitch of the deck. IE set the rear at a notch lower, then higher as compared to the front. Different things tend to happen w/ different cutting systems. This would also be a good way to see how your local Honda dealer will earn your future business.

Thanks tomplum. Actually, this was purchased "ready to mow" from a Honda dealer. A bit of history. I purchased the commercial HRC216HXA back in 2009 and experienced the very same issue. I figured maybe their plastic deck would possibly have a better/more efficient design so I tried it. I've gone to the dealer several times with the commercial one, tried a gator blade, took off top blade, contacted Honda, etc.. I even changed wheel heights on that one as you suggested. Will try on this one. Cut today and looks worse than usual. (I put the upper blade back on.) My wife says it's because it was so tall, but my 19 year old Honda my inlaws now have still cuts perfectly with grass as tall as this was. Here are some pics.

Just a secondary note , since your in a Southern Region . Within the approx. 6 mths have you resharpened the Mower Blades ? Mulching units require additional attention for Quality cuts , with your extended Growing Season . I even noticed with my 22" Toro Recycler that Optimium Mulching Cutting height was achieved through trial and error with a single blade configuration . P.S. Ensure that the Air Foil edge is kept clean also since this assists with lifting the grass for the secondary blade cut.

Actually, I put a clean edge on all 4 cutting edges before mowing this last time. Still not understanding what's going on under the deck. Some of the stragglers are still rounded on top (not cut at all), and others are still tall but cut somewhat I assume since the tops are flat. Not sure if there's too much turbulence and blades are getting blown down or what. I was on the fence between this one and the Honda powered Toro Super Recycler. Now wishing I'd gone with the Toro.

I imagine you have tried alternating the deck heights , otherwise as Tom suggested perhaps a trip to the Local Dealer is Warranted .

That will be next (altering wheel heights). Been raining daily during the time I can mow, so hopefully the next day or so will allow. I do have to be careful about cutting heights though, as St. Augustine is vine-like and grows across the surface as it roots. Because of this cutting too short can do a lot of damage to the grass. Another option with this mower is to vary how much the clip director is or isn't open. I was hoping that keeping it open on the 1st or 2nd notch from being fully closed might improve airflow and create a better suction. Downside is it didn't help much and blows grass out behind mower which leaves clioppings on the yard. By the way, thanks to all for your suggestions.

MN: All the Best Bro , sorry we could not resolve your issue , please let us know if you confirm the cause !

Will do... Thanks to all for your help and suggestions!