Yes LHR is terrible, so give yourself extra time. No rational person would choose WBC over CW. WBC truly is the bottom of the business class barrel. The only excuse for it is necessity or because it is much cheaper than the equivalent. I flew it last week out of necessity and I can tell you 19 hours in a pretty threadbare old combi with grumpy FAs and without any compensating benefits like a nice seat or decent catering (IFE was good though) was pretty rough.