We're quickly approaching the final OmniGraphSketcher 1.0 release, and today are making RC1 available via software update and the download page.
Lead developer Robin has added some more optimizations for dealing with larger .ograph files, as well as fixed some nagging bugs and crashes. We now interpret parenthesized numbers as negative when importing, and sharp-eyed users will notice a refined selection highlight. OmniGraphSketcher's rectangular selection tool is now more consistent with OmniGraffle's (finding all graph elements that intersect with with the selection rectangle). This release also features a complete help document.
You can read the full release notes here or from the Help menu within the application. As usual, please don't hesitate to send us your feedback and any crash reports that are generated. While version 1.0 is feature-complete, we've got great stuff planned for the future.