I have toyed with ASL ring, and did well in puppy matches, and am a member of a GSD club where the ASL is the typical line of members.
I would not show the dog in a specialty show because you will just waste your money, and probably be the recipient of some nasty comments. I mean, as hard as it is to get enough dogs together for a major, a member of my club entered her GSL dog to help them get a major, and she heard some really crappy comments from other people about her dog. I don't think you want to expose yourself or your dog to that.
GSL dogs do better in the ALL breed shows. If you have a nice working line dog, I have to think he would do better there than the specialty rings. And I think there are sieger shows here in the US. That might be your best venue.
There really is too much politics in dog showing that you will ever see a Czech dog be put up in a specialty conformation show.
Arwen, CD RN CGC
Whitney, RN CGC
Tori, RN CGC
Jenna, RN CGC & Babs, CD RA CGC HIC
Heidi, RA CGC
SG3 Odessa, SchH1, Kkl1, AD
Ninja, RN CGC & Milla, RN CGC
Joy, Star Puppy, RN CGC
Dolly CGC & Bear CGC
Hepzibah & Hannah