Haven't looked recently but you were always able to sign up to an online trial for £1 with no cancellation issues.
Having said that I no longer have any faith in their reviews based on buying a few of their "Best Buys" that turned out to be pretty poor. Something that seems quite common when you read user reviews of them.
I type items name into a search engine and read quite a few different sites reviews.
Doing that is what lead me here when I was researching AV equipment.
I paid £289 in the very catalogue for my condenser dryer beko ( it was that expensive purely due to it being black) costs about 50p in total to do an economy wash in my new beko washer plus dry them, 7kg load capacity top of unit water trap and a light inside the drum, bought my son a similar white one but his is 6kg capacity £189 from AO
Another annoyance I've just remembered with Which? reviews is that they seem hopelessly out of date. Several times I've looked for a price on a Best Buy, only to find that the model number tested has long since discontinued.