It really depends upon what you are using it for, but in our business of insulating and keeping crawlspaces clean, it's not a good choice even though it's an industry go-to.
Fiberglass insulation is only effective as long as it's flush against the surface of the space it's intended to insulate and that's the problem with a crawlspace. The moisture in a crawlspace causes the insulation to get heavy with moisture and then the insulation pulls away from the floor above. Now, cold air can creep in between the insulation and the floor, rendering it useless. Additionally, rodents just love the stuff and will make homes out of it and they will urinate in it, and since 50% of the air in your home rises up from your crawlspace... well, you get the picture. Consider Cleanspace Encapsulation to get the insulation quality you deserve and save money on your utilities.