While A-List Drummer is "GM compatible" it has missing several tom and cymbal slots. The toms are also mapped in an unorthodox manner so using GM mapped loops with it can be very challenging.
If you'd like to use our loops with A-List drummer, please email support at groovemonkee.com and we'll send you A-List Drummer files for any purchase.
We discussed other options for using MIDI drum loops with Reason here. The best option is usually their standard ID8 Drum sounds which are mapped for GM and generally sound good. We also supply loops for the NN-XT Kits and for the now discontinued "Drum Kits Refill". The NN-XT kits are not mapped consistently so your results will vary.
If you use A-List Drummer, please let us know. If there's enough demand, we'll add it to our officially supported formats.
Enjoy the freebies and rock on!