Swiss Cottage - How long will they wait...
 

at the airport for me? If we need to exchange tube vouchers, get money, check tourist info, etc. Also, I'm confused about the rates. Just Airports specifically says round-trip. Swiss Cottage doesn't, but basically same rate.

My first suggestion is DO NOT book Swiss Cottage on the web. If you call them you can get a definitive price and information and the rate will be a LOT cheaper. You can use the following complete number dialed from the US and the call will be billed to your home phone number at a cost of 4.9 cents per minute.
101-6400-011-44-207-431-2700

On the other hand, Just Airports seems to be beating all the other competition, including Swiss Cottage these days.

Hopefully you will follow Patrick's advice but your questions about Swiss Cottage are clearly answered at their website. They confirm the time your plane lands and allow 30 minutes of waiting time. After that, it's prorated at $12/hour. Other than grabbing some cash from an ATM, why would you need to do those other things at the airport?

Last week I booked a car with Just Airports for an elderly friend travelling to London and if this is the page you were looking at (http://www.justairports.com/prices.htm), please be aware those are definitely not round trip prices. Round trip is an option on the booking page.

Those are not the rates I was comparing - I entered as "from airport & return" and got rate of 66 (I think Swiss was about 40 each way)??

Swiss cottage is cheaper when you book by phone. The rates via the website are apparently £10+ higher.

And I agree w/ obxgirl - why do you need to hit the tourist office and exchange transport vouchers at the airport? Since you are not taking the tube you can wait to change the vouchers til are in central London. The queue at the LHR Tourist Information Center can be quite long - plus it is in an inconvenient location for meeting your driver.