Wanting to upgrade a Motobecane Super Mirage with a more modern freewheel than the worn out Suntour unit on it. Looks like I'm between 2 Shimano freewheels a HG37 or TZ21. Looks like they have a slightly different design with respect to the finish and the way the cogs are locked on. Is one preferred over the other ignoring the tooth count differences between them? Is one a higher spec (eg. Tiagra vs Claris)?

HG37
imgur.com/0j1Eb0d

TZ21
imgur.com/ARbgRSK