While I can't answer the question, it is important to note that Hitler did not join the German Army because he viewed it as "better" than the Austrian one, he joined the German Army because he believed it had a purer racial character.

To go back a few decades prior to German unification there were two paradigms to the "German Question" of a German state, these being Kleindeutschland and Grossdeutschland (Gross meaning large and Klein meaning small in German). In laymans terms, Kleindeutschland meant a German state without Austria, Grossdeutschland meant a German state with Austria. Obviously the existence of both a German Empire and an Austro-Hungarian empire means that the former was the answer. Hitler's birth citizenship and nationality may have been Austrian but he viewed himself as an ethnic German.

To fast forward to the start of the Great War, we have an Austro-Hungarian Empire who's territory stretches into the Balkans and is made up of a number of different ethnic groups (Czechs, Austrians, Hungarians, Slavs, etc) and we have a German Empire that's predominantly German. Hitler spent the prewar years in Vienna and he was disgusted by the racial diversity of the Austrian capital. There's bits in Mein Kampf where he mentions watching the Austrian Parliament and seeing parties of rival nationalities screaming at each other in their native languages while the government accomplishes nothing. He ends up leaving for Germany in 1913 and was not a German citizen when the Great War broke out but apparently no one checked that when he volunteered for the Bavarian army (There were a lot of volunteers at the start in most countries, the Great War was quite popular when it broke out).

In summary, it's very likely that Hitler viewed the German military as superior due to it's racial character but not due to anything that had a basis in reality.

Source: Richard J. Evans, The Coming of the Third Reich.