I did not perceive a belligerent attitude by the Brazilian consulate in Miami...nor did I, or my friends, ever had difficulties. I really do not believe they scrutinize the application all that much - It is just a reciprocal visa policy, and cannot at all be compared to what the US puts Brazilians through to get a US tourist visa. At least for US citizen's it is pretty much guaranteed to get the Brazilian tourist visa, but many Brazilians pay the cost to get the passport and then pay the tourist application fee, just to get denied!
As far as visa timeframes - my friends have gotten a 10 year visa recently. When I applied for my first tourist visa about 6 years ago, it was issued for 5 years. Now, fortunately, I have Brazilian residence (my wife is Brazilian), again the paperwork was straightforward and it was a relatively simple process. Actually I remember a Brazilian consultate guy joking with me during the process - he told me completely straightfaced and serious "You forgot something, there is an additional fee"....with a proper pause and wait for a look of surprise by us, followed by "....for every Brazilian woman you need to bring 5 American women to Brazil, preferrably blonds, but since your wife is very pretty make that 10 in exchange". My wife and I talked and joked with him awhile afterwards, but certainly a good experience!