hdfc regalia card good?

How old is your millenia and the current limit if you don’t mind

If you don’t travel a lot (for using free lounge access) and cannot use reward points for hotel/flight, never go to Regalia. It can be viewed as downgrade if you use the card mostly for shopping and want to redeem rewards as cashback

looks like

millennia has reward cap of 5% CashPoints up to Rs 1000 every calendar month

while regalia gives 4 Reward Points per Rs 150 spend

Regalia has international lounge access but millennia doesn’t (even domestic lounge access is less in millennia compared to regalia)
Milestone benefits – get 10k points on spends of 5L and additional 5k points on spends of 8L on regalia. For millennia spend 1L in a quarter and get 1000 voucher.
Smartbuy benefits – regalia has smartbuy benefits to get 5x points upto 4000(2000 capping in a single day) and millennia has cashback capping of 1000 per month.
Reward program – 4 points on spends of 150 on regalia(1.33% if redeemed for travel, else 0.7-0.8%)
5% cashback on preferred merchants(Zomato, amazon, Flipkart etc)
1% cashback on all other transactions (except fuel) monthly capping of 1000 points . No capping on regalia.

This post should help you. 

https://cardmaven.in/hdfc-bank-regalia-vs-mille...

If you do not plan to use up the reward points for travel, then opt for Millennia over Regalia.

Pls stick with millenia
If u get LTF regalia only then u can take

Millenia is cashback card while regalia is for points accumulation. I personally think millenia is better than regalia because smartbuy flight and hotel booking with points is crap. 

I won’t suggest since it’s not LTF.

I upgraded ltf regalia to paid millennia….

it is effective only from Feb-2022, earlier it was cashback