The latest HRR models now have a Clip Director, although it is an "on-off" version, compared to the HRX's variable position control. Pay attention when shopping and be sure you are looking at the most current model.
Side-by-side in heavy, tall, wet grass, it would seem the more powerful 190cc engine in the HRX will outperform the 160cc engine in the HRR. Both have the same warranty, but the mower decks vary; the HRR has a painted, stamped steel deck.The HRX's NeXite deck is a molded-color polymer material (much like a car bumper or football helmet) and won't rust or dent like steel. There is a lifetime warranty on the HRX's deck (original retail customer only).
At the risk of making the decision even more difficult, you might consider the HRR216V
YA. The Roto-Stop (blade clutch) is a tremendous feature, even if you mulch 100% of the time. While the Honda engine is generally a breeze to start, being able to "let go" of the handlebars and just the blades stop [engine keeps running] is awfully nice. Here's a video (Roto-Stop @ 2:01):
Honda HRR216VYA Mower Operation
Most Honda dealers participate in a little-known program called The Honda Commitment. The short version is, buy a Honda mower, use it for < 30 days, and if not happy, dealer will apply full purchase price toward any other Honda mower of equal or higher price. So, if you buy an HRR, but it does not "cut it," you can trade up to the HRX and not lose a penny of your purchase price.
Before spring hits, you might want to shop for a gently used Honda for maximum value. A used HRX, some with electric start, may be found for even less than the price of a new HRR. Any warranty that might be remaining on a used Honda stays with the mower. Most have a 3-year warranty, some even have 5 years if the original owner participated in the warranty extension promotion. With the serial number off the back of the mower deck, I can check the database and let you know if there is any warranty left. The serial number is on a sticker on the back right of the mower deck: