My buddy runs a crew in Airdrie and he always tells me the big name insulation places are the ones cutting corners, not the smaller guys. Last year he pulled out R-20 batts from a job that was supposedly done by a well known Calgary company, they were half crushed and stapled wrong. Sounds like you found a solid crew who just wanted the work, four days is quick for a basement that size. Good for you, honestly, it's nice to see the cheaper quote actually work out for once.