Check out the sound and user interface of the OP-X with the provided demos. They have the same sound as the full version while having some restrictions. If these start getting on your nerves then buy the full version.

		OP-X VST PC Demo    Cubase 5 issue fixed / new period Limitations:                                     Need a free vst host? - trial period limited to 10 days - periodical noise bursts - requires restart after 15 minutes - not compatible to library - saved patches not reusable download (3,3mb)    contains several trial banks
		OP-X Reaktor5 Mac/PC Demo Limitations: - limited working time - random beeps - several controls don't work - no sync to song tempo - restricted preset number download (0,5mb)