I read your original post. My take is that you're not really getting "downleveled" as you believe to be. Larger tech companies are picky with what experience they value. They don't value you "basically being #2" at a company they've never heard of. They have no way to evaluate if that's a good thing. If you had done great during your interview, you'd have been offered a higher position.

If you want to make more money, now's the time in your career to jump to bigger tech-ier companies. I had to go through it myself, and things started getting much better for me rapidly.

In conclusion, your "it's a downlevel" is a moot point. It's not a con; go with Capital One if you value more money in the future.