I love reason.

But only for the following:

The Subtractor+Matrix edit combo.
The NNXT via rewire... the NNXT is one of the best samplers i ever used. Reason v2.5 takes up very little CPU over rewire.

*Here's a tip... if you want interesting looping patterns connect the matrix pattern seq from the CV or gate out to the back of anything, such as the subtractor, into on of its CV inputs for perhaps FM or Phase or anything you fancy really and set the pattern to an odd length, say 5,7,9 etc and randomise the pattern... The note sequence will loop as normal, but the modulation will not, and will create some superb sounding variations*