This is a post I did a couple of weeks ago on the British Athletics Weekly forum.
Here's the situation in , which I believe will be replicated in pretty much all countries
BBC Mainstream Channels - Most important events chapped like thin slices of sushi and mixed up with each other along with plentiful blethering, montages, previews, interviews, reviews and news. Also will be constant channel changing, so if you expect to watch the Big Race starting at 17:59 on BBC1, you will be switched away to BBC2 , then have to sit through credits, blethering, an interview with Keely H, a feature on Keely H's dogs, Gabby, Denise & Jess's opinions about Keely and only then see the Big Race at 18:15 by time you will already know the result.
BBC Red Button - A bit better, in that it will be full uninterrupted coverage of your match, session or whatever, with just a quick introductory voice-over before getting on with it.
BBC iPlayer - Will only show what has previously been shown on one of the other BBC Channels. Usually slow to post, so if you want to see something that took place at 08:30 expect to wait to about 16:00 before it is up.
Eurosport 1 and 2 linear channels packaged on Sky, Virgin etc. Usual Eurosport style. Big solid bleeding hunks of live action. Introductions and reviews don't overlap the main feature, but are shown before and afterwards, or at worst as picture within picture. Nowadays, lots more adverts than there were three or four years ago. Lots of repeats overnight. Familiar well-informed commentators & experts. Advert-free option available if you are paying for Discovery Plus.
Discovery Plus Online - The only place to see every single thing being broadcast with dozens of streams going at the same time. Available on all major hardware platforms and devices. You'll need good broadband, multiple HDMI inputs on your TV and home wifi. Apart from the stuff which overlaps with Eurosport commentators will be from the World Feed. That should be OK for Athletics where it should be familiar voices. Also multi-tracks (usually without commentary) for all field events, uninterrupted long races etc. Commentary a bit less reliable for minority sports as New Zealand horse-racing commentators attempt to get to grips with canoe slalom, Australian Rugby League commentators do synchro swimming etc. But you will have to pay at least some kind of monthly fee for the length of the Games, possibly even a longer contract. So start looking out now for bargains and offers.