Wasn't season one the only season that ILM worked on? Could that account for the difference in F/x quality?
I'm not seeing anything too worrying in the released images so far. I'll reserve judgment until I'm watching it on my TV.
IIRC, ILM only worked on EaF
, which included building up a library of shots for use during the entire series (they also did the lovely matte painting of Deneb IV that didn't need replacing). Otherwise the same F/X house (can't remember the name) worked on S2 as worked on S1.