I know very very little about Tetraspis breeding, I think C2 should be a more stable version color wise but I have only heard someone mention as much so a rumor of a rumor I suppose (yet how most orchid info gets established

). If I had to pick the C1 or the C2 I would pick the C2 but that is me, I have heard lots say they prefer the uneven wild look of a bit of color everywhere. It seems to be what a lot of Tetraspis keepers like about the variety.
I prefer more uniform flowers and it sounds like the C2 is a flower spike machine so that is always good if they improved that too. They both look amazing. But I really like your C2.