We lived in Windsor for around 5 years when DH was working in Staines. Our house was within 15 minutes easy walking distance to both railway stations. DH used to catch the train at Windsor & Eton Riverside direct to his office in Staines and I could use the same train to go direct to Waterloo, though it is a relatively slow stopping service of just under an hour.
From Windsor & Eton Central, it was really just a small shuttle train direct to Slough where you change for the fast train to Paddington; around half an hour all in. (No Elizabeth Line when we were there).
So depending where you need to be the rail links for London are pretty good.
I preferred the slow train to Waterloo mostly as Windsor was the end of the line and you were guaranteed to get a seat and have a nice sit down for an hour.
DH had to use Heathrow a fair bit too, and there is a nifty back road from Windsor into Terminal 5 which was very handy when DH came in late as it took easily less that 20 minutes door to door to get to the airport to pick him up; consequently I never left home until I saw his plane had actually landed 🙂
Of course, there is plane noise, but you do get used to it, I know I did. We were right under the landing path and if we were in the garden we would just stop talking for a few seconds. The big jets used to come in very early from Hong Kong etc and after the first week I just slept through it. It was a small price to pay for living there.
We loved it in Windsor, so many beautiful parks and walks, and when we were there if you were a council tax payer you got free entry to Windsor Castle all year round (I don't know if that's the case now). I enjoy living in touristy towns so it being fairly busy all year round, and very busy in summer, wasn't a downside for me, always someone to chat to in a cafe or pub!
Racecourse had lots of events going on, not just racing, you can catch a boat there and back, always something on the river to do even if it's just feeding ducks. Beautiful walks along the river too. The occasional celebrity wedding at the Guildhall! There's a great brewery with it's own bar and food spot, and some decent restaurants.
Shopping is good I think, Daniel department store was useful and there were plenty of the more upmarket chains. Waitrose in the centre was our corner shop really, but there were bakers and delis aplenty.
I don't have small children, so can't speak to that experience, but there were certainly lots of young families on our street and there seems to be plenty to do. Decent little theatre with panto at Christmas for instance, as well as all the usual family events in the parks etc.
If there was one thing that I would call a downside, it's the parking situation; we had no drive so on street parking (which is by permit) could be a bit tricky on occasion, which is no fun when it's raining and you have loads of shopping or small children! Also, you may find you are suddenly very popular with friends and family who want to visit; whether that's a downside is debatable. 😄
Any questions just fire away.