Actually, I think Surface is more entertaining than Invasion. If Invasion doesn't show the "creature" real soon, I'm getting pissed. I also think ABC's Invasion is losing viewers to CBS's Criminal Minds (in the same time slot); probably why it replays on Satuday nights.
Since I watch way too much TV, of the new "creature/alien" shows this fall, Threshold is the better of the three. Friday nights at 9pm on CBS.