I had one chin at first and he seemed happy on his own, but I decided to get him a cagemate anyway. I only really have time to spend about an hour a day playing with my pets so I felt he would like the company. So I got another male and bonded them, they're now the best of friends and it's very cute to see them together. I'm pretty sure he's happier now than he was when he was alone.
The downside is that he no longer likes interacting with me... at all! He used to enjoy being stroked all over, would climb on my arm etc, but now he is extremely wary of me and only really trusts Jerry (that's his new cagemate). He hates it if I go to touch him or pick him up. Jerry's a little more outgoing but still not as friendly as my original one was when I had him on his own. They do tend to bond to humans better if you just keep one, but whether that's a bit of a selfish reason to keep one alone I don't know...
Anyway, if you have time to give him a lot of attention and he seems okay I'd probably be tempted keep things how they are. It's personal preference really though. I'm sure your guy will have a happy life whether he's alone or in a pair =)