1012 was the last solid build. I'm running 1014, which caused problems for enough people for it to be considered risky. 1018 is probably a guaranteed brick, it's too close to the flash limit hence the suggestion to use their linux utility.
Sadly that thing doesn't work either, happily, several pages back, someone wrote a quick guide which does and several forum member here who were critical or requested previous build had their ips banned from the dgteam forum. Basically, if you disagree with them, or tell them a build is bricking routers, you get brushed aside. Then again, it isn't open source either.
Although I have to wonder about people, capable of coding an adsl routers firmware for technically aware users, who choose to spend time banning ips which as we all know, makes accessing or posting completely impossible

Oh, and you'll get banned for uploading a previous working build of their firmware if they catch you.
If your isp is someone like Be who let you change your target snr (3,6,9db) then draytek make an excellent modem. Getting another GT would be cheaper, but you'll also need to get 1012 from somewhere.