Not a lot of use these days Max, in my opinion.
All it does is centralise what we already have, and in a less good way.
Option 1 just runs the BT Wholesale Performance test then the Further Diagnostics but only returns the down and up IP Profiles. It also prevents you doing the same for several minutes. Twenty I think these days, not the few hours it states - which used to be the case. If I'm going to do that I'd rather see the speed test results as well.
Option 2 simply invokes the standard BT Wholesale checker with the Postcode submitted into the address option. Which gives a drop-down list.
Option 3 simply invokes the standard BT Wholesale checker using the phone number option.
Note the footnote on the page