O2 are weasels with a download limit that isn't in their paperwork or selling material. This on a premium account that was costing way more than the base level one.
Singularly unhelpful too.
And the f'wits still send me survey links asking me to rate their broadband service.
That's not really an O2 limit, that's a BT limit being passed on down the line to you.
If you are connected directly to O2 equipment at an unbundled phone exchange, then O2 don't enforce any kind of download limit. I'm sure they must have a "fair use" clause written in somewhere, but it's not applied. I can download literally hundreds of giabytes a month without so much as a murmur from O2, and this is on a base £12 a month package (used to be £10!).
Where a customer is not within range of an O2 unbundled exchange, all O2 can do is rebrand and re-sell the same woeful BT wholesale based offering that so many isp's are stuck with, hence the crap prices and crap download limits (that product is called O2 Home Access). In those circumstances the O2 offering is nothing special at all, being essentially a generic BT bundle.
But, if you can get the true O2 network offering, their value/performance is head and shoulders above anything else I've seen.