330 FO to 320 CA was largely a financial wash on the W2, if not a little less as captain. I spend a lot more on food but get far less per diem.
My hourly rate is higher, but by virtue of the domestic operation, seniority, per diem and time/money spent commuting, it's probably net less than 330 FO.
If you want to make bank, senior widebody copilot is where it's at.
QOL was far higher on the ER and the 330 in the right seat compared to the 320 left seat.
It just really depends on what you're after. For me, it was more than time to upgrade, but the "newness" wears off after about a year and you kind of tire of the moments where you have to make heavily unpopular decisions. Some people are going to love you and some people are going to loathe you and it's just part of the job.