Review sites for the hardware wallets? As I understand it there are four (4) hardware wallets produced currently (2018).

Which businesses, web sites, or academic papers in the field review and compare the security of these devices?  Is there such a security review?

(Just TBC by "review" I don't mean, "this one is a nice color" etc. - security review.)
I've never heard of a site that has done an in depth review of the security of these devices. The common point of difference on the hardware security is this: 'The TREZOR is essentially a small computer while the Ledger Nano S uses two secure elements/chips."
Otherwise, a lot is the same for other hardware security such as no WiFi or Bluetooth.