On the surface this is very easy to use, and if you just want to make simple beats it's not hard to get going with it and it's self explanatory. You will definitely want to peruse the manual on this thing though - there is kind of a confusing amount of settings you can go through for every sample and every beat you make. Other than adding the effects I mentioned you can't really edit the samples that much, but they give you a ton of them so it's not hard to find something you like.
The sounds on this thing are great. I prefer them to a lot of sample packs that I have on my DAW and I end up exporting a lot of sounds from the XR 20 into my DAW sequencer for studio use. It definitely specializes in hip hop type sounds - if you want just a plain realistic sounding acoustic drum kit this is probably not the piece of gear you want. The effects are fair - they do what they say but don't sound as good as a lot of the plug ins you would have on your DAW. The expressiveness of the pads is only about fair as well - the velocity curve on them is kind of tricky and takes a little bit of getting used to. I would probably stay away from the reverbs on the XR 20 and leave that to a different program.
I have been using this for over a year now. I love the great choices of drum sounds and the sheer amount they give you to work with. It's also easy to set up songs and sequence part changes and fills which is nice. The XR 20 also lets you do some melodic stuff - the drum pads also have note values so you can program in simple synth melodies or basses as well. I have tried a lot of drum machines, and this one has great bang for buck. I would get it again.