Re: underground. Let's face it - you're going to be using it anywhere you want to go in London. The question is how much time & how many tube lines you want to switch to.

MA is much better set up locationwise, and it's not like it's a major hardship to switch at the end to a dif hotel. And FWIW - keep checking stays - something might open up.

Having said that, you do get to stay in one place w/ MV. But it's a possible 20 min extra each way from MV to central London.

Also, I know you want to use points for Paris, but the Euro exchange rate is better than the GBP exchange rate so you might want to take that into consideration when figuring out where to do the paid stays.

Cheers.