I've not seen any reports on here about speed in Chells, but if you get what you are paying for at off peak times, and then it drops in the evening, get ready for a VM Rep' to tell you that your line is over subscribed.
In chells just spent 27 missus on the phone whilst they did tests. resent information to the router. Unplugged router. Discount white cable. Etc result is same speed as before 54mbs they then told me there is fault in the area and it should be fixed by end of the month. Told the lady not good enough as have just upgraded and want compensation for lack of service. She then told me that she has sent the compensation request to the department handling them.
Ah, the joys of the offshore call centre. Fixed by the end of the month, yep..... Their scripts tell them to give fix dates, but in reality it'll only be a review date. Welcome to the everlasting cycle of reviews.
"Fault in the area" is the key phrase. We're still using the cables that me and my mates laid in the 90's. Cabletel didn't even imagine 200 meg' internet, and VM haven't upgraded it since. If you get given a F Number, be ready for a long wait to get your speed sorted out.