See
http://whitecoatinvestor.com/choosing-an-hsa-provider/ for a good review of HSA plans offered by the providers listed below.
The article generally recommends
HSA Bank or Fidelity HSA
It also covers
HSA Administrators
Alliant Credit Union
Stanford Federal Credit Union
Wells Fargo
Adirondack Trust
Lake Michigan Credit Union
Bank of the Sierra
Any of the above might be "best" for someone, depending on one's specific plans for an HSA. You could compare Sterling's plan with these. Don't know what their fees are. Yes, a $48 flat fee on $1200 is 4% - that's a lot to pay for access to "commission free" options.
Also, the article is a couple of years old so things may have changed. If anyone knows of a material change, let us know.