If the fish were slender like an angel, or moved like an angel, they would be an option. I found them as aggressive among themselves as any angel, but heavier bodied (bioload) and nowhere near as nice as a scalare, I know in the older texts from Axelrod, for example, he said they could replace angels, and I bit on that hook.
The pleasure in watching angels, to me, is on how they move. They are a graceful fish, when they aren't committing murder. Mesonauta have the angel style 'feelers'/modified fins, but to me, the comparison ends right there. I really wanted that fish at one time, but found it grew into an unattractive fish, in time.
I found them as aggressive as angels - no more, no less. I always bought groups, as I would for angels, and they always established a pecking order that necessitated moving the weakest to another tank. I had them in a 75, with the low ranked fish going into a 55 to recover before I rehomed them via our fish club.
Many people love them though.
I always bought small groups of angels and grew them out. And I always had to move some of them to other tanks. I had a pair of Colombian wild caught scalare that had become enormous, with great fin growth before I moved. I didn't think they'd survive a winter move with a 10 hour drive to a temporary set up. For all the aggravation they caused me, I miss them and would get more in a heartbeat. There, I had started with 4. One was killed, one was rehomed and the pair never spawned, but were huge.
