Reason works great for me as a pre production tool when I work with bands. I can easily set it up in PT and focus on arrangments and proto types before any recording is actually done.
It's got some alright samples, but I rarely use it as a tool in production. Maybe for some background effects.
If I had to rely heavily on MIDI sequencing, then I would go with Logic (plus hire a genius midi tech).
However, midi is like kryptonite to Lee and he dreads it ever so dearly.