Note that SOFI checking is only 6 months old, at this point. This is because SOFI acquired a bank earlier this year. Any experience before this is with SOFI Money, which was through another bank.
I signed up first for the SOFI credit card, then for SOFI Checking and Savings, in April. I got the credit card because my two both added foreign transaction fees, even as I was planning a trip to Europe this summer. The card also pays 2% cash back, when deposited into their bank.
As a new thing, I did see teething problems. Particularly with time for deposits to clear. It's pretty good now, with next day or even same day clearance. I don't know if that is better integration, or that I now have some history with them, re: where my deposits come from.
Overall, it's been OK, and getting better. My Ally money market has been slightly faster in increasing rates following Fed moves, but SOFI has kept up. (I do not have direct deposit, so am not getting that bonus)
They are also app-first. I still fins things that I can only do in the app, vs. On their website. But, they are working to match capabilities. This is a rational choice of priorities given their targeted customer.