At a glance the remote control for the Pioneer HLD-X9 seems fairly similiar to that of many other laserdisc players.
The one on the left is the remote control shipped with popular machines such as the Pioneer CLD-D925, CLD-2950 etc
The one on the right is the remote control shipped with the Pioneer HLD-X9.

As you can see it is the exact same size and shape however it does have a number of different buttons and associated features.
D-EXT button let’s you toggle back and forth the correct NTSC colour temperature for Japanese NTSC and the U.S. standard. So, both U.S. and Japanese LD’s will look their best.
In effect it lets you get deeper blacks if you want them. I don't doubt this can also be achieved by just adjusting your TV settings although it is very handy to set via the remote which you can conveniently toggle.
Video memo and select buttons let you configure the 3D comb filter using either pre-defined or customisable settings.

I wouldn't mind getting some advice from someone who knows more about how to actually adjust these settings properly.
Audio Mode button displays on screen a number of configurable audio options available e.g.

Strobe play facility can be turned on to drop some of the frames but maintain the sound. In effect the image will look like a series of stills even though the sound plays as normal.
As a music fan I found this pretty cool as you could effectively pause given frames to look at in more detail whilst not interrupting the actual concert playing.
The long grey button on the left side of the remote illuminates the main play buttons (white buttons) for about 5 seconds with red LEDs which automatically dim and gradually extinguish.
FL DIM button controls the dimming of the display on the front of the unit which again has a range of settings from low, medium and high brightness to not shown at all.
Display button can be toggled to display a number of LD options including the remaining time on the LD (for a given side) which I don't think I've seen on any of my other LD players I own.
Surprised this wasn't a standard feature on other players as it is an obvious omission that is useful.
The Multi-speed button offers 1/90, 1/30, 1/16, 1/8, 1/4, 1/2, X1, X2 and X3 speeds. The 1/90 and X3 speeds are not usually present on most other LD players.
NOTE: The normal remote that comes with other laserdisc players (e.g. black one shown above) can be used with the HLD-X9. The reason I mention this is because one feature I use frequently as a music lover is the Audio D/A button which toggles between Digital and Analogue audio. This button is missing from the HLD-X9 remote and instead this functionality must be controlled by pressing the Audio Mode button and selecting the relevant options via the on screen display. I found this a bit tedious to access and prefer the old remote which you can use to toggle the audio much faster. Funny how you get used to certain features and really miss them when someone makes a subtle change! Thankfully the old remote works with the HLD-X9 so you can use it if you prefer. Conversely the HLD-X9 remote can also be used to control other LD players for any features they support.
One shot memory button - I haven't figured out what this is actually for. Can someone please let me know!