I 've kept them with Vieja, Parachromis, and plenty of other south and central Amercans, and Madagascans without a problem. They hold their own with most, but don't back down.
Id say is subjective. If I could find a 4-5 inch pair for $120, Id get it in a heartbeat.
As far as aquabid goes, Ive ordered 7 times and only 2 times have I gotten what Ive ordered..and one of those times it was dead. I guess if you order from a legitimate seller that is a member here, you might have better luck. I didnt and Ive had crappy luck there.
Again with this topic, but I just dont believe a LFS is selling "Wild Caught" 3-4 inch festae for $6.99, so be careful with that as well...not saying I dont believe whoever posted that, just dont believe they are WC or even festae probably.