3 Minutes to Change Trains at Twyford?

You should be able to do it but even if you miss the train to HOT, another one will come in 30 minutes. The 2 tracks on the southern side mainly have High Speed Trains shooting through to Wales & the south-west.
http://www.nationalrail.co.uk/stations/TWY/details.html

theres wiki for it with photos.
Theres 5 platforms, and an up and over bridge connecting them. I'd be doing deep breathing and leg stretches before the train pulls in..

Looks like your arrival is on platform 3, the departure is 4 which is the shortest distance

The station supervisor there is a bit of a character - retires in September.

Great read, Marco. What is an MBE?

We will be there in mid-October so it appears we will miss seeing him. I will plan on taking an earlier train from Henley so we have some wiggle room if we do not make the connection. We will be on our way to Heathrow so don't want to get there too late!

We had a three-minute connection at Crewe on or last trip and did not even try to make it, as we knew we would have to go upstairs and cross over the tracks to the next platform. It was supposed to be 10 minutes but our train from Glasgow was running late. People on Tripadvisor had advised me that even ten minutes was tight for that connection. So we chose to wait an hour for the next train rather than try to make the 3-min. connection. As it turned out,we could have made it---the next train was in the station when we pulled in but maybe it waited for people from the Glasgow train to transfer? But by the time we realized we could have made it, the train departed.

MBE = Member of the Most Excellent Order of the British Empire.