Although it's appealing to see this primarily through the lens of Apex' big weakness (no non-virtual resources) the bigger effect on Apex may well be to give it access to a wide range of very efficient tools cheaply. Although many of the most expensive programs have rotated out a few remain:
- Mass-Driver is rather situational (2 per sub but you get to ignore up to 3 subs on the next piece of ice) but if it works it's really quite nice. I wouldn't use it without something like Inversificator to help shape the ice though and that means a heavy import price.
- Morning Star is a very efficient (though memory hungry) fixed strength fracter: 1 for any number of barrier subs as long as that barrier has strength 5 or less (good thing for the corps that Parasite is gone, Ice Carver isn't however).
- Inversificator is on the cheap side of what I'd call expensive (the 6+ range) but it's an excellent breaker (and restricted).
Hardware has seen some of its most expensive pieces go away in the rotation as well, but the all time biggest credit eater is still there: Monolith. It doesn't synergize very well with Apex since the ability to prevent brain or net damage is worse than what Heartbeat already gives you but the 3 is nice and I guess it's at least a nice surprise during a game to turn up a hugely expensive console. Oh, wait. Console. Right... Yeah, it doesn't synergize with Apex at all unless you want to skip on Heartbeat and you don't want to skip on one of the absolute best Apex cards.
Ignoring the consoles the most expensive hardware is Adjusted Matrix. I guess it could be nice in the right deck, having the option to click through ice could help when Endless Hunger doesn't quite cut it.
On the resource side Rachel Beckman is nice. The shards (Eden, Hades and Utopia) were already available to Apex (virtual) and could already be installed without cost under certain circumstances, but having a way to buy them for a few clicks and otherwise leaving them as fuel is good for Apex. Plus the shards (and Beckman) are only 1 influence so they won't bust the budget.
Liberated Account becomes much more efficient if you only pay for it. Laguna Velasco District and Professional Contacts are also interesting, especially given Apex' need to draw cards.
A somewhat circular but slightly amusing option is to save 5 on installing Assimilator. Just in case you wanted to have a second one handy.
Aside from the expensive stuff Assimilator is perhaps even more effective just doing its thing in your deck since it lets you replace + X to install a card normally by Apex ability + . I don't expect this to be a complete game changer that will make Apex viable on a championship level, but my gut feeling is that it will make building a somewhat competitive Apex deck a lot easier.
Addendum: What I forgot to mention is that Assimilator has a small but nice effect on the game. It lets Apex have more hidden information in the form of face down cards. Normally only the corp lets their opponent play a guessing game.
Addendum 2: There's also a nice benefit with Apocalypse in that if you have an Assimilator on hand when you Apocalypse you can recover much faster from it than the corp by flipping your most valuable cards face up again.