Sonia and Tom seem like an odd pairing to me. For one, she's five years older than him.
As for Nick and Heather, I think she would nitpick him the way she did Derek although as far as we know, Nick isn't messy/smoke pot. Also, Nick has a temper just like Derek does...he would probably go off on her. If he went off on sweet, way too accommodating Sonia, he would definitely tear Heather a new one...
On a different note, I think Sonia and Nick are done because she is taking shots at him on SM.