The toxicity of mercury is highly overrated, but you are right, the mercury ones are a toxic waste clean up by today's standards if they break in a public place. I have heard of them closing off rooms in public institutions for things as small as broken mercury thermometers.
One of the big things in the public space is that when you produce over a certain amount of toxic waste, everyday items that you used to be able to just put in the normal waste stream become regulated. Like dead single use batteries and even empty bottles of white out.
Anyway, I would probably go with a wall mounted mercury unit if I were to buy one. I have an aneroid now. A lot depends on the look though. Given I am not a real doctor I am a bit more concerned at how it would blend in with the other stuff in my exam room than it's absolute accuracy.