With the carronade/flame combo, it took us several 3 or more minute shifts of sustained fire on a Spire to bring it down. It is effective, but impotent against better loadouts or when not used in conjuction with other ships.
I have recently discovered I hate the chemspray. I prefer the one-and-done of the extinguisher.
I've recently been trying pipewrench/buff hammer. Some hate it, but when the wrench puts a good portion of the hull back, it's nice to not have a forever cooldown where you can't put another shot on the hull and you only needed half of the repair HP the hammer gives. Plus, with the rebuild effectiveness being 4/5 of the spanner rather than the more severe 2/3 of the past, it makes a reasonable case.