I also feel freely comfortable discussing engineering, math and the hard sciences in general. I can actually do pleasant small-talk really well but only briefly - after a few minutes I think people start to notice that I get strained by it. It's like trying to operate a mannequin with controls for the eyes, mouth, posture, head angle, verbal intonation, word connotations, while simultaneously sending and receiving encoded messages and pretending to chuckle at the same things as the speaker and to be somber or angry if the group around you decides to go that way in conversation.
I'm in a support group for people with ASD and I find the verbal nature of the communication is an obstruction (although may be necessary in the short run). But the level of identification and understanding is wonderful anyway. 
One funny thing about language - I got exposed to German in a truly wonderful program for kids with, dev disorders when I was between 3-4 yrs old. Then at 4 I got pulled from the program and only English was spoken to me under awful circumstances and I was eventually mainstreamed which truly sucked with my kind of autism. I definitely feel better about German, like English was this monkey-speech forced on me by impatient, angry parents and plastic learning machines, rewards and punishments that had no meaning to me. Then it was the language I had to respond to when I was mainstreamed into public elementary school. And better respond right, or risk getting called names or hit or kicked. Unfortunately the inability to communicate the same way as an NT - instead of motivating people to work harder on mutual understanding (like in.some ideal world), it most often seems to lead them to try to correct me or they get frustrated with the communication and move on. Basically that leaves me isolated. I need to cop to some old, deep resentments about having language forced on me I guess. I was not a happy baby, lol, and I remember.