I searched the article in vain for data to back up the headline. Nothing: no survey, no comparisons. Just a few self appointed experts complaining about overcrowding, which the opening of Terminal 5 next year will help.
Please do not misunderstand my point of view. I dislike Heathrow intensely. It's just the least worst of the options. Gatwick is south of London - much further to fight around the always congested M25 - and Air Canada does not fly to Stansted, which is closer to where I have been going recently.
And there is nothing in the article about Terminal 3, which is the one Air Canada uses. Which is, quite simply, dreadful. By the time I have got to the Piccadilly Line from the plane I feel like I have walked further than I have flown. (That by the way is pardonable exaggeration for effect). On the way out of Britain you are forced through a huge duty free store and then made to wait in a mall with no area to sit which is calm and peaceful. No doubt this is designed to make you consider paying for one of the airline's executive lounges. Like all malls it has a food court, with very limited choices, and horribly overfull bars. No natural light and no windows. And, by the way, Duty Free does not mean profit free. While it may seem to Brits that prices are lower than their high street stores, they are definitely not anything like the regular price less the taxes. And they are also not geared to international travel. For example you can only buy British standard DVDs - not ones you could take home and play (unless you are a technogeek who can get around the differences between incompatible tv systems).
One interesting little fact is that you can buy duty free on the way in to the country. You cannot do that in Canada. But be warned, for most things (for example a bottle of Blue Sapphire Gin) you would be better off buying it at your departure airport in Canada.
But undoubtedly the worst feature is the long line up to get through the totally inadequate security area. In fact, BAA themselves recognize the weakness of this arrangement as there is a special bypass route for those making connections - or (no doubt) having the right connections. That is why they tell you to get there so early. You will spend most of that time in a long, long line up, trying to get into the departure area.
The sub editor could be right. But the lack of data to back up the assertion does not add much to the Independent's credibility