Surprised that there isn't a review here yet. Lets fix that!
Here are the major differences:
- No need to run it. It stacks by itself, doing instead of chisel what parasite used to do, taking care of ice all by itself, albeit slowly.
- No need for rezzed ice. Put it anywhere you like and watch the counters trickle in.
- No strength trigger. 5 Counters = dead, whether it's a 0 strength Vanilla or an advanced Hadrian's Wall.
The main problem of course is that ultimately the corp has the chance to counter it, Cyberdex Virus Suite and Cyberdex Sandbox are also not unusual picks, a desperate corp will lay down those 3 clicks, but anytime you pressure the corp into a round like that is a small win for you. In a program suite that includes other good targets for virus support like Conduit you might have some sort of plan brewing, just be careful not to overcommit, or else you might be the one feeling the tempo hit rather then the corp when it purges.
I think this card shines best as a 1 or 2 off with a bit of tutor support, try it in a deck with Gachapon!