I've been using Rex Control deck for a while and haven't lost many times to glad beasts... Especially because my deck is focused on banishing the oponent's backrow cards and/or making them useless with cards such as Gyokko or Seargent Electro.
The thing is: any deck can be countered, no matter how strong it is.
Play Aroma deck or REZD budget deck against It. I always win If I Play using those deck against GB. For Aroma's strength is combo with Rose Lover to protect your monster by Trap (usually Training Shield or WoD) and for REZD, you should do spec. Summ. As much as you can using Gozuki's effect and take control 1 GB monster with E-Con