It’s not my deck, so Calimsha could probably sum up things better, but I’ll give my 2 cents after playing a few games with the deck today.
So far I think I like Wormhole. With Grim and Archer in the deck, I’ve found it usually becomes another program trasher, but one that reads “code gate, bitch.” With a strength of 7, it is a very real threat.
As for advancing it, for me it’s depended on my situation at the time. If I’m super good on cash, then paying 9 to trash a key breaker or stop a key run is fine with me. Plus if you are advancing it, it can telegraph what it could be, which allows the runner to play around it better. There are other times when I have advanced it because I knew I needed to be able to rez it this turn, and this was my only way of doing so. This has the fringe benefit of allowing you to advance an Ice Wall to bluff another Wormhole in a situation where the runner could simply break it, although, as you said, it can be a tempo hit to do so. I haven’t had to do it yet, but I suppose the possibility exists out there somewhere.