Sorry to hear about your medical issue. Hope all turns out on a good note.
I have lived in both 3 story and 16 story apartments throughout my life.
I would prefer a low rise apartment building. Less people, less drama. If your not into that shit trust me they will show up at your door lol
Also bugs and creepy crawlers which happens no matter if you live in a elite building or not, they will go everywhere. But being downtown increases the chances of bed bugs, cockroaches, mice etc etc showing up in your life. Buildings are close to food businesses etc. The more tenants there are in a building the higher the chance of those things getting in the building.
When your looking for an apartment watch the fridge and stove carefully (even pull them out to take a look) as that's where the roaches love to be.