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 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 DISCONTINUED AND REPLACED BY OP-X PRO-II
		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 DISCONTINUED AND REPLACED BY OP-X PRO-II

NOTE: OP-X is a legacy product and has been discontinued in favour of its big brother OP-X PRO-II.