I actually carried my duty weapon on my ankle for many years (compact 9 or 40cal...my last ankle carried weapon was a Sig 229 in 40 cal)... I found it very do-able (and for many years after I retired out the inside of my left ankle still showed the marks...). At my current age, 70, I'd never consider it. Matter of fact I'd never recommend it to an armed citizen since it requires some serious effort. Yes, you can reach it instantly when seated - and while sitting at a table, if I chose, I actually could rest my hand on the weapon without the others at the table being any wiser... but you're significantly slower in most situations. The real advantage, if done properly - is that you appear un-armed... until you're not.
South Florida was an exciting place years ago (too exciting at times...) but I never found that carrying a 12 or 13 shot compact auto pistol to be any disadvantage at all. I will say, though that if I had to run - the sidearm was in my hand - not on my ankle... In my case every mode of carry depended on how I was dressed (you won't have a weapon on your ankle while wearing shorts...) and if I was wearing a coat and tie a waistband carry was the only way to go... Wearing only a short sleeved shirt and trousers though I found the ankle carry to be just right. Yes, it's slow to reach, yes, it takes a lot of getting used to... the real advantage is that you appear un-armed if there's an armed opponent in front of you - and not a particular threat.... I started out only carrying a five shot Chief's special on my ankle but learned through experience that if you were in any kind of a possible armed encounter - that you really needed much more firepower. Unlike an armed citizen - as a cop you're obligated to act, and you'd better have what it takes with you...
Glad I'm out of that world -and haven't carried a sidearm even once since I retired out in 1995....