I just started with fire mouths this month so I have been doing allot of research. I purchased a breeding pair and have 75-100 fry.
1 - they are good parents.
2 - a bonded pair will (typically) stay bonded for life.
3 - they are tough little buggars but the fight by bluffing (flairing there gills). There mouths are made for sifting not really fighting so if you have them with more aggressive new world cichlids make sure they aren't locking jaws because there's could get ripped off.
4- Since they like to sift sand substrate is better.
5 - I am finding they are very personable fish and will interact with you right from the start.
6 - If you are keeping them right water, temp and diet are all good. Their colors are magnificent. If any of those things are off they look washed out.