The current Upgrade Extractor in the Gem Store is not worth its cost. Along the lines of the Infusion Extractor Device, an Upgrade Extractor Device should be available in-game for silver and the Gem Store should sell a Permanent Upgrade Extractor Device. The ability to easily swap out sigils and runes from gear would be fantastic.
I know this has been discussed in the past, but it is a very pertinent issue. It will create flexibility for players to test out different builds as well as adjust gear for different game modes or situations.