Hannibal I think it was you I talked w/ this b4 over PM, I had 2 exos in w/ my spilo, they were probaly bigger than him at the time, and they were getting the best of him, I had to take them out. He had one's tail all nipped up, but besides that, I think he was scared of them
He's bigger them then now, so I think the results would be different, but I put the exos in a 10G, bought another one, and I really like them, active lil guys. In the end though, its up to you, just give them some hiding spots to give them a better chance if you decide to do it. By the way, how much are exos where you are, they run around $5 here.