tachograph:
I don’t know of anyone who’s actually done mods 2 and 4 instead of 35 hours periodic training that cannot be failed but it’s an option.
I did and wish I’d gone down the 35 hours route. The mod 2 and 4 can be failed and if you have a pre 97 licence its a right royal pain to book those two tests.
I think the 35 hours likely teaches more too as long as you do sensible courses with decent tutors.
ADR just has the advantage you get 2 courses for roughly the price of one if you do it somewhere that has a CPC registered course (not all do).