I've previously been with Westpac and CommSec and still...

I've previously been with Westpac and CommSec and still have a Westpac Broking account but transferred my 2 major broking accounts to SelfWealth around 4 years and 1 year ago respectively.

$9.95 Flat Fee
I have my own HIN (like the bank platforms) so the holdings are registered in my name
My cash on the SelfWealth platform is held in a separate account with ANZ
OSKO cash transfers from my normal bank account work well
US Trading if that's your thing
App isn't quite as good as some banking apps but I've not had any real problems. Trading is generally fine on app or web and I prefer SelfWealth's reports on app compared to what I get from Westpac.
SelfWealth is listed on the ASX so I can inspect their solvency and accounts for myself if I so choose.

I wouldn't class myself as a frequent trader but at an average of say 2 trades/week I'm saving well over $1K pa. Some have suggested STAKE as cheaper but I prefer the transparency of a publicly listed company (each to their own). You should certainly do your own due diligence. I didn't move everything at once but set up an account to try it out. I only moved when I was comfortable.

Bottom line, I've been a very happy customer. To me using a bank broker is a bit like using bank retail super funds over industry super. Lazy tax.