I mean, I think that's been pretty obvious. Dastrn and I are brothers and work well together, so it's not unexpected that we gel well in a mafia game.You think Dastrn/Xatres are working together? Why not say that earlier instead of now?
And yes, I agree with RR. If Gheb were to flip scum, it reflects well on us. If he flips town, then it reflects poorly. Gheb's flip also sheds light on all Gheb's reads and opinions (we'll know if they were from a scum or town perspective) and sheds some light on the people reluctant to vote for him now. So yes, there is stuff to learn.
On the topic of J: I said before and I'll repeat here. I don't think J's flip will give us nearly as much info as a Gheb or Spak flip does. J's push on Ryker at the beginning of the day fell perfectly in line with my thoughts on Ryker (and several others) early in the Day. Since then J's been relatively inactive. So to me, J's really not an option. If you go for the inactive/policy lynch, we're better off removing TSYK. If you go with actual scumhunting, then J's lynch gives us very little info, and I haven't got any compelling reason to think he's scum.
So of Gheb and Spak, I think Gheb's the best choice between those two, for reasons already stated in detail.