"You say the transported Jews weren't gassed, shot, burned, etc, but you have no plausible or detailed account of what happened to them. Well, I prefer to stay with the established story until you have a better account of where these millions of people went."
There is some validity to this, though it is not decisive. We have detailed revisionist studies of the individual camps (Auschwitz, Maijdanek, Belzec, Treblinka, Sobibor, Chelmno) and revisionist work on the Einsatzgruppen is beginning to appear (Vincent Reynouard's recent videos, Mattogno's projected work scheduled for the end of 2017). These however, largely consist of objections to the alleged mechanics of or evidence for illegal killings.
To illustrate the problem: people were deported or sent to Auschwitz. There is some information on numbers (Danuta Czech's Auschwitz Kalendarium, Hilberg, for example). There is evidence (unquantified) of people after the war being transited through displaced person camps and ending up in Israel, USA and other countries or remaining behind the Iron Curtain. Is there though, no more that can be done to fill in the intervening period?
There is little granularity on the numbers of people deported (lists of names do not exist, at least for one camp, so I am told). Hence, the numbers of deportees may be questionable. I am not aware of much information on what possible destinations there could have been.
The main points though, are:
1. Upper Silesia where Auschwitz was located was the center of an industrial region for which Auschwitz was the Stammlager (Stalag, source camp):
https://www.ushmm.org/wlc/en/media_nm.php?ModuleId=10005189&MediaId=5009
Is there any coherent, quantifiable account of people arriving elsewhere in Upper Silesia from Auschwitz? The Auschwitz camp records have survived. Are there no records from the other camps or factories in Upper Silesia?
2. What about records of people being employed digging anti-tank ditches, living in towns or employed in agriculture further east than the Aktion Reinhard camps? Surely these would generate paper work (orders of work to be done, supplies being paid for, etc) among a variety of army and civilian institutions. I know that Mattogno et al devote 100 or so pages of "Extermination Camps" of "AR" to the subject in 2013, but there is a lack of adequate detail, as is widely acknowledged.