CitiPremier miles is a good general card as the miles don't expire. However for me, I am using OCBC 90N, also miles don't expire and you can change in blocks of 1,000 miles. Only downside is that it's only for Krisflyer miles and no lounge benefits. If you have an UOB One account, you should have at least 1 UOB CC also (miles/cashback it's up to you). Reason being is that if you can meet min. $500 spend per month, you would be able to hit your UOB One account criteria (Assuming you have 3 GIRO or salary credit to it). Also, UOB One has a tie up with Grab, where you can get up to 10% rebate on it. This is insane. I only just got to know of how good a deal it was! On your last point to be loyal to one bank, no not really, you should select the credit card which suits you!