I use Westpac and have for years for 'investment stocks' and are...

I use Westpac and have for years for 'investment stocks' and are on their sight everyday all day with watchlists etc and have never had a problem although I do remember then going down once. Hate their platform though....very basic. I guess they want you to upgrade to Trader Pro.
I use a cfd provider for short term trades.

One thing also is that you don't have to sell your shres with one broker and buy with another. You can simple transfer them and no cost or trade activity is incurred.