Please feel invited to do a root and branch comparison between Inkscape and any other vector drawing program that you already familiar with. See http://mikesalsbury.com/mambo/content/view/231/1/ and http://www.ex-astris-scientia.org/misc/software_test.htm , take a look at the last two paragraphs of the second URL, about 95% of the way down.
Sorry about the delay in replying, it is just that locating the Ex Astris page is quite tricky because it doesn't have many useful keywords!
Note that version 0.44 of Inkscape is in its final stages, and right now would be a good time for people who are interested in testing and comparing to take a cool hard look at our work - it really could a make a difference. I've not yet seen a Universal Binary, but it is hoped to make a UB of version 0.44 . If 14.1 MB is too big to download, you will find the software on the disks of some Mac magazines, and in source form on many Linux ones; otherwise make contact withe a nearby Macintosh User group or Linux User Group. You are sure to find someone who will hand you a copy: It is one of the things that User Groups are for. The Yorkshire Macintosh User Group is based in Doncaster, but we do hold meetings as far North as Bedale.
You might want to point out that Inkscape is an SVG (Scalable Vector Graphic) editor, and as such its files are future proof and full inter-operable.
Ben