I too have just been buying a washing machine. also spent ages poring over the Which report. In the end though, I found a lot of the recommended ones weren't in stock, even over the internet, or they took ages to deliver or charged a lot to deliver and install.
So, I went to a local electrical places in town. They've been around for 30 years or so. I had a good chat with them and decided on a Bosch. Got it delivered that day and installed and old one taken away - for free!
All friends who have Bosch say it's worth it. Most reliable above all other brands. The shop have Bosch deliveries twice a week because they are so in demand. If they are a bit more expensive, I think it's worth it for overall reliability.
The shop engineer also told me not to bother about going up to 1400 rpm as this wasn't always good for your clothes. Also, Bosch are so energy efficient that they are outstripping the energe ratings. Mine is an A-plus or something similar!
Since I've had it, I have been so impressed. Much quieter than last one (which was Hotpoint or Hoover and called a 'Whisper' model - my arse!).
My model cost around 360 pounds. Love it!
Much as I love Which, they only test some models. And then new ones come out which aren't in their tests. Also, it's about deciding what factors are most important to you. And, having been without a washing machine for weeks, reliability comes top. These days, most top brands produce machines that clean and rinse - that's the essentials!
Hope this helps. Let us know what you buy.