@lupincode, my opinion is still pretty much the same. I like Guardian/Cobra since they offer lower commissions than Centerpoint. The stock locates at all 3 are great, tho like I previously said, having more than one broker with stock locates is important if you are a full time daytrader. If you are a new daytrader, starting with either Guardian or Cobra is a good start.
For shorts, accounts at all three would be ideal.