I know it’s one of those things that people either believe or they don’t, but I’ve never had an amp that doesn’t sound better after being on for 30 minutes to an hour. I don’t bother seriously listening for at least an hour.
There really isnt a comparison between the Heritage line and the Best Buy home theater lines. But I think this is exaggerated because most people that buy the Best Buy stuff also run them with Best Buy type HT receivers that don't necessarily bring out the best in the Klipsch.