Wow, one guy spends $75K a year on his credit card. Wish I had that kind of money. I don't have to worry about the MBNA (Fidelity) card going over, there is no way I'll be spending that kind of money a year, especially since I use another card for gas and groceries (5% cash back).
As for Upromise card vs Fidelity. I think it's a no brainer, I had both before. But here's points vs your points:
"1. I like that Upromise is linked to Vanguard accounts. I understand I could always get a check and deposit it anywhere I want, but I value the automatic feature here."
Fidelities is an automatic feature too.
"2. The Fidelity plan has higher fees than Vanguard and an annual fee (at least the ones I looked at). I could avoid the annual fee by making monthly deposits, but don't really prefer Fidelity in the first place."
No fees if you simply place $50/month in there. Then every year just fill out a 6 to 8 blank form to have everything transfered into whatever 529 you want.
"3. Since I already have a NY plan, it was easy to have deposits going to my NY plan."
No biggie, you can still have it directed into NY plan.
"4. I get a NY tax deduction on my Upromise contributions."
OK, so this adds what? 6% to your Upromis money ... instead of doubling (or 100%) if you used Fidelity.
"5. I believe anything extra that Upromise gives me by registering my citibank card at Upromise I could also get by registering a Fidelity card at Upromise. However, it is just simpler to have everything go to one account than have both Fidelity contributions and Upromise contributions."
For $300 extra a year I'd fill out a 6-8 line form every.