I've had both good and bad results from Great Stuff.
It's great to seal a hole around an electrical outlet or stop air flow.
But it can produce much more pressure than I thought possible around a door opening. Enough pressure to move Sheetrock and molding enough to cause problems with the closing of a door.
Also, if you've never worked with Great Stuff before, a little bit can go a long way. More is not always better. If you get it on your clothes, they're trashed. If you get it on yourself, it's next to impossible to get off. Very messy stuff.
If you don't have time to do it right the first time, when will you have time to do it over?