I've been with CapOne since about October 2018 and started with a Quicksilver One. I got a Platinum in March which I was just able to upgrade to a Quicksilver (so 3 statements).
Not sure what the criteria is as the card was still in credit steps as well. I check the upgrade page occasionally and it popped up so I figured why not.
Congrats on the approval for the Quicksilver! It's a great card!
Regardless of the lowly opinion some people on these forums have about Capital One, I think they are a good lender to work with. Overall, I've been very satisfied. Even though I have cards most people would consider to be much "better" than my Quicksilver, I still like it a lot.
Being able to redeem instant cash-back as soon as the charge clears pending is a huge exception in the credit card business. (Most banks have minimum redemption such as $25. For example, on the Citi DC, that means you can't redeem anything until you get to $1250 in new charges.) Some cards require you to redeem points into a bank account or Fidelity investment account or PayPal account. Not Capital One. Also, redemption against your outstanding balance is easy and there is no penalty in point value for doing so. (For example, you lose 1% when you pay with Citi DC for paying your balance with points. Or get only 1% on Fidelity if you redeem for cash. )
They have a good website and app, and their fraud prevention was right on top of it when my account was compromised.
My only Capital One gripe is they have lower SLs than many banks and are very reluctant to raise them unless you're putting a heavy spend on the card. Their 'high limits' are much lower than other big banks. Requesting higher limits is also very automated and you can never find a live person to talk to or reconsider whatever they are offering.
Overall, though, I think they are a very good large bank and I recommend them!