I'm pretty much in the same boat as you. I had my first SA, and am working toward the new levels. For me, it's mostly about the achievements and getting to play some different levels (I used to use
https://imgur.com/a/OTDDS1L a lot, but now I've basically memorized where all the hospitals and markets are on all the levels). I've been heeding the warnings of others, so I've been hoarding powers (I have 33 TW, 45 SAC, 62 SM, 53 FC, 13 MR, 41 FB, 22 IM, 5 SL, and 9 ML). I'm hoping that will help me navigate through them without feeling stuck. I think the 10x IM is going to be my savior. But I'm still completing the levels (including the hardened) sequentially so that I have the AP to get there (plus it helps my OCD personality). We'll see...