1) It isn't their consensus best album, which pretty much cancels the notion that the group wasn't critiqued. It also cancels the notion that the group was just their. People that aren't die hard Kast fans point to any of their albums that isn't Idlewild as their best. Each album brought in new listeners. Some liked the new directions, others were critical.
Kast doesn't basically say their first was their best. At most, you have Big Bo in saying SPCM needed that other half mic, because it was a classic.
3) What albums sound like ATLiens, Aquemini, Stankonia, and Speakerboxxx/Love Below before those albums came out?