Quoted from IdahoRealtor:I'm in the same boat as you and chose TWD Prem. It ships Friday.
Looking beyond all the obvious pluses of GB (which is probably worth buying as well), TWD has completed code, likely won't be available NIB much longer and most importantly it's a Borg/Lyman pin. Same team as Metallica, Tron, Iron Man, etc. They're like Jordan and Pippen.
So, it was a pretty easy choice for me. Stern will be cranking out GBs for at least 2 more years. No rush there.
I did the same thing. I got my TWD Premium a little over a month ago. I love the GB theme, but the truth is I've gotten very little playing time on that game (I haven't seen one on location, and there is always a line at shows). After Stern's PF issues are resolved, I can look at getting a GB down the road, but I am really loving TWD.