I’m not fond at promoting FB but besides being a nice guy, ElcO, a french Quake 3 Defrag player and mapper, has started a page on FB for his work using GtkRadiant : Elco Mapping.
All of his maps are available at Wolrdspawn.org, here is the direct access to the full list. If you’re interrested, you may also check the thread on the defrag.fr forum dedicated to the runs on his maps ^^
You may also watch Defraging is not a crime, a brilliant video made by breacH, to see some great runs and tricks performed by ElcO.
Keep it up dude ^^