The two are not mutually exclusive. You can check Ts & Cs and also ask for peoples’ experiences. FWIW I did go ahead and order, and I did check the Ts & Cs. Ts and Cs say that you can return even after delivery as long as the bike shows no signs of having been used outside. It is useful however to get a feel for “real world” policy. eg. Some companies are difficult re. returns, others have are very straight forward as a matter of reputation. If I heard numerous stories of protracted delays in issuing refunds I would have reasonable cause to be weary.
The law in the EU is actually very clear as to an almost absolute right of revocation and return for Online purchases. This is due to the fact that you do not get to see and feel the goods as you would on the high street. With most companies pursuing your rights is quite straightforward, but unfortunately with others it can sometimes turn into a battle of attrition.