despite all the ho-humming about VST support (or lack there-of) inside Propellerheads Reason, I think its brilliant that you can accomplish so much with just reason, an understanding of complex routing, reason rack modules and the combinator device.
things are tight at arena studios money wise, so I'm very picky when it comes to dropping money for new VSTs or sample packs, but I can't recommend Nuclear Soundlabs Filter Research refill highly enough. The efx patches within this refill are truly mind blowing and will change the way you produce. For about 30 USD or so, its also a steal. Highly recommend for the Reason users out there. The page has a nice quicktime movie walkthrough and you can of course download the demo to try it out. Thats all it took for me to fork over the cash!
