Geos are a great fish, very active and colorful. I had red head tapajos in the past and currently have iporangensis, both were housed with severums, silver dollars, an ebjd and a nic. The EBJD and severum like to mind their own but never back down from another tankmate while the nic is trying to claim half of my 125 but the iporangensis have succeeded in keeping him in line. Never any physical damage just a lot of posturing, sometimes the geos will get just close enough to annoy the nic and piss him off on purpose. The red heads were less aggressive but also fit in well with the same stock.
I have some similar dueling going on right now, only resulting in physical damage. My 3" Orino thinks he can run my whole 125, biting and nipping and gill flaring. My littlest 3 Pbass actually have splotches of white with bitten scales, torn fin webbing, and the littlest one got some dorsal spines broken because he gets picked on. Pbass are brutal. My 2 Orinos and 1 Mono are the 3 big boys, but only one is being a bully. But today my biggest Ocell bit him back a few times so I hope he's getting some balls.
Anyway, yes, I saw a Geo at the LFS 2 days ago and I was totally impressed. They're sooo pretty and appear to be pretty smart. And I'm not sure on all of these cichlidisic orangasiligus names they have going on so I have no idea what those fish are! haha. I know what silver dollars are though! ; )