The BMP can be changed in many, if not all, of the ones I use. That is one criteria that is essential to me.

MIDI loops can be varied over a much wider tempo range than ACID type audio loops without causing artifacts.

You can also very quickly change kits or presets for a very different sound even if you don't want to tweak.

Glyn Barnes
Audio loops, particularly multi-track loops, will take up a awful lot of disk space...
[...] I can’t always find exactly what I want so editing or creating the loop from scratch is an essential feature. [...]

Indeed, creating MIDI tracks for drums and other instruments from scratch is a huge time-saver for any composer/arranger. While songwriting and quick demos benefit greatly from using loops.

Another alternative is to use a plugin called Jamstix. I have had it for quite a while and it offers some of the benefits of a real drummer (not everything is necessarily on the beat or predictable, for example) but allows for tweaking the accuracy. It also will play drums in such a way that is actually possible for a real drummer to do it (it has knowledge of the fact that a drummer has only four appendages that they typically use for the performance). You can use it with its own drum sounds which are pretty good, or you can use it to drive EZDrummer or Superior Drummer. It's definitely worth having a look.

Are Drums on Demand already processed?

Justgotpaid - thanks for the kind words. We're still at it - just transitioned to an all-new site this past spring. If you remember the old hard copy CD days, then that goes back a while!
 
We've added a lot of drum loops since then - take a look if only to see what we have been up to since we began serving up those "lushy, live bar-room sound" grooves you dug!

chuckebaby
but when its crunch time and you want the best possible sound. mic up a kit and get yourself a drummer.
I know this is not practical for everyone but real drums blow away any sample made.
there are certain nuances about a drummer, real drums that can not be captured no matter what you do.
even a poor drummer itself can bring a lively feel to something any sample can not. which is a robotic, flat totally in time drum line.
I know some will say, but theres things you can do to make them sound real. those people are right, there are things you can do to make drums sound real. trust me i know. ive made a video on it here:
https://www.youtube.com/watch?v=ruAnAPR6-hQ
 but that's just it...the difference between "Sounds real" and "Real" are miles apart. 

As a drummer myself, Thank you for saying this.  I have always felt this way, but thought that live drummers were going the way of the 8 track tape...