Lots of things were just said that I have not seen happening in my games...
... One of the strongest features of Sunny is that she actually has a reason to run Link, that she actually gets use out of it with the Nexus. Now, that said, nothing says you have to run Link... I've been investigating a build that ignores Underworld Connection in preparation for rotation... But it's been subpar to every build that at the bare minimum includes 3x Sports Hopper or 3x Rabbit Hole to get your Link up to 5 with the Nexus (6 if you installed all 3 Rabbit Hole/Hopper). Five is the magic number because suddenly the Corp has to pay YOU to stay out of the Nexus trace. Power Tap takes the place of Link until you hit the fifth Link, and then suddenly Power Taps pay you back.
Additionally, Security Chip also pays Sunny back for actually picking up Link, becoming stronger than a Stimhack in the later game once you have the full SunnyBreakerSuite out, walking through servers for less than half what it should cost you... Furthermore, Security Chip happens to be one of the very few cards in most Sunny decks that she can afford to lose, meaning it gives you some security against 1000-cut PE/PU decks.
I absolutely agree that Jak Sinclair and Masanori is good. I don't agree that this lets you keep up with CtM, because your weakness vs CtM is 100% money-related. You need money to get out at least 2 extra Link, then suddenly that stupid ability stops mattering and you can go and trash all their things. CtM is a miserable matchup for Sunny just because of their sheer speed. It very much comes down to whether they get a Sensie before you're set up to actually meaningfully contest their board. The good news is that Nexus happens to be really good against Tollbooth.
The upside of Jak + Masanori is getting a free card every turn. The downside is that the Corp suddenly has a much larger incentive to pay to deny your Nexus trace. The further downside is that a card per turn doesn't help against decks packing HHN.
The second-best option I've found is Multithreaders+Datasuckers. They just take More Time to set up and don't really help Sunny out in early game where she needs it. Overmind, however, DOES help in the early game and I've found that to be the best MU use for Sunny. I've considered Magnum Opus, but haven't built a deck for that yet. As a side bonus, the extra MU being available is what makes Data Folding an enticing include for Sunny decks.
I did try Faust Sunny for a while, and found that unlike most decks, Sunny doesn't have a lot of redundant cards you can afford to pitch, and also doesn't have ways to recur trashed cards in general outside of Same Old Thing. This also lends to Sunny's weakness against PU/PE decks, by the way.
Uh, her programs are why she has a good late game. If you have oodles of cash, they happen to be among the best breakers. Especially at 0 influence. Basically you get to play Better-Aurora, Better-Force of Nature, and Repeatable-Mongoose influence-free. Those aren't the best breakers, but if Criminal can get away with it, so can Sunny.
Striker is definitely the worst, though. So, if you were to declare one unplayable, Striker's definitely the one. (Mostly because of Enigma, but 2 for a Quandary is also appallingly bad.) Just so happens it tends to be not as terrible against some of the new code gates running around... (Fairchild 3.0 for 6 is better than anything not named Torch, Cyber-Cypher, or Gordian Blade.)