My HSA is sizeable so really like its own IRA.
I have been using CONNEXUS with VERY good experiences. They were paying 2% on balances back when most all HSA accounts were less than 1%.
BUT times changes. I am now moving my HSA to Fidelity. Still some 5% broker stuff available, so cannot keep the funds at CONNEXUS. I did check to see if they were changing the rate anytime soon ..... and was basically told NO. It's 2%.
IF they get the rate back up, I would use them again. BUT they would have to be better than Fidelity.
FYI - I found a pretty good review of various HSA providers at: