[Xiaomi Mi Note Pro] Aqq123:
TL;DR Warning: Scroll to the bottom if you just want the conclusions.

The original author, ethan2k on the MIUI English forum, claimed to have unlocked band 8 on Telstra in Sydney:

However, gadgetwhisperer, another user on that forum, pointed out to him:

Until now (up to post #86 in that thread) there was no follow up on the above suggestion.

According to the website OzTowers.com, which has a list of mobile bands by provider in Australia, the majority of Telstra's network is on band 3, while in the New South Wales (NSW) area, of which Sydney is the capital, they only have 2 (two) base stations on band 8. To quote the relevant part of the table at this link as of January 2016:

Gen Spectrum Band ... NSW ...
... ... ... ... ... ...
4G 700 MHz 28 ... 320 ...
4G 900 MHz 8 ... 2 ... <
4G 1800 MHz 3 ... 985 ...
4G 2100 MHz 1 ... 4 ...
4G 2600 MHz 7 ... 30 ...
^

The reason? Already in September 2014, Telstra announced they were cancelling their 900 MHz (band 8) services:

Moving on, in the original post the author states:

First of all, the bands 1, 3 and 7, underlined in the quote above, are enabled by default, so they don't need to be unlocked. That leaves the following bands supposedly unlocked by the author: 2, 4, 5, 8, 17, 20, 28.

The author suggests the required change to the settings to enable those bands:

Converting the suggested decimal value to binary, for example using Google's "2061853925599 to binary", we can see which bits are set:

11110000000010000000100100010000011011111 < Value
4 3 2 1 0 ^ Bands
10987654321098765432109876543210987654321 (vertical)

You can see this setting then enables the following bands:

38-41: TDD LTE

1, 3, 7: already enabled by default

2 ,4, 5, 8: this part is OK, does what it claims to do

14, 18, 21, 29 - ?

As for the last line, bands 18 and 21 are only used in Japan, each of them by a single network. Of these, band 18 is obsolete and is supposed to be replaced by band 26, of which it is a subset. Bands 14 and 29 are not used by any commercial networks anywhere in the world at all. You can check this for yourself in Wikipedia.

In short, enabling those four bands is most certainly useless. So, what happened? Most likely whoever was doing the calculation wanted to enable bands 13, 17, 20 and 28 but shifted a part of the number one bit too much to the left. Anyone can make a mistake like this but with so many people following this guide it could be reasonably expected that someone would spot it before.

I am skipping the discussion of the changes to the other values, which concern 2G and 3G settings, but in my view the suggested values are even more off (particularly so if you have the All-Network version of the Note Pro, it'll actually disable some of the originally enabled bands).

To wrap it all up:

I appreciate ethan2k's posting of the whole tutorial complete with the necessary software links but it appears he has been misled into thinking that he was connected on band 8 while in fact his phone was using band 3, which worked by default without any changes.

The value calculated by ethan2k was OK for attempting to enable bands 5 and 8, which is what he wanted to try, but a mistake in the calculation means it does not really enable all the bands it claims.

So far

no-one has had any results

with the changes but it seems

most people tried the values that were not correct

either. If you want to try changing those settings, do it properly. That is:

Start with the values read from your phone (not some magical, mysterious number found on the Internet)

Convert them to binary

See if the bits set to 1's match with the bands that should be enabled by default

Change the bits that enable the bands you want and

double-check

Convert back to the original base the number was in (decimal or hexadecimal)

Write the number into the phone

Report back the results with all the relevant details: Phone model, Baseband & ROM versions, Bands you tried to enable, Original values, Replaced values, Network you tried it on, Whether it worked or not. Don't just say "it worked" because the phone didn't explode the moment you changed the values to some garbage.

This way we might actually get somewhere with all this

one day

.

To find out which bits in the settings correspond to which bands you can see my post here (particularly for 2G and 3G, as for 4G LTE it's simpler and already explained above). I can't vouch that what I wrote is all correct but at least this way you have a chance to check my reasoning for yourself because everything is described step-by-step and referenced. I encourage everyone not to take anything about the band settings at face value and reproduce all the steps on their own. Also, if you find some better sources of information or spot a mistake, please share it so that we can all learn from it.

Let me reiterate that with my post I didn't mean to criticize ethan2k or anyone else but I just want to clear up some confusion that built up, and propose some more rigorous way that will hopefully lead us to a definite conclusion on whether more bands can be enabled and if so, which ones.