Open Inventor SGI vs TGS

Is there a big difference between SGI and TGS Open Inventor? Is the TGS licens very expensive?

There is an explaination of differences at this link http://www.tgs.com/pro_div/oiv_vs_sgi.htm.

As a 3rd alternative you might want to check out:
www.coin3d.org

Hey all,

I was wondering if someone already done/seen some comparison between Coin3d and TGS’ Inventor performances ?