Hexadecimal, interpolation, 09xx (just recently learned it got changed to 0Sxx,

)
oh my.
It's really not that complicated and if you use vsts primarily, you probably won't have to learn how to use the pattern effect commands much. I prefer not to make my patterns all cluttered with command effects unless I'm getting crazy with samples. like experimenting with timestretching/granular resynthesis with the 09xx effects.
If you type in anything in the pattern, it will show what it means in the bottom left corner and will tell you how to use it. If you have any questions, I'll be glad to help.
But what makes it special for me is how fast I can work with it. Navigating through the lines and tracks with the arrow keys, tab, home, end, page up, page down, delete keys is so much faster than using a mouse. You're moving through the lines of the grid, perfectly snapped and don't have to worry about getting a mouse cursor in just the right spot.
Just to go through the keystrokes I would use for example:
1. After loading up the 808 instrument the comes with renoise into instrument slot 00, hit escape to turn on editing mode, start tapping Z(first note, C on the computer keyboard for playing notes like a music keyboard) and delete to insert the bass drum notes and spaces in between(you can get into a groove with this, it's much better imo than clicking into a piano roll for midi drums).
2. Ctrl+T - Create a new Track. Do the same, but with the S key for the snare sample.
3. Ctrl+T for the third track. Just hold down V and editstep will create a constant hi hat loop for you in a second or two. I just inserted 32 hi hat notes like that. bam. I didn't have to click 32 times into a piano roll. Or click 4 times and copy and paste and copy paste and..... wow, like who thought piano rolls were a good idea in the first place?
And I just created a simple little drum loop. Press escape to turn off editing mode and press spacebar to play and listen to that beat you just made in less than a minute. Really if you just try it for yourself, you'll see how nice it is.
Also the tutorials and demo songs are great for learning how to use renoise, how to make certain sounds, and great to steal samples from.

And theres the Renoise Q and A thread
http://dubstepforum.com/viewtopic.php?p=1212509