I've not flown from Luton for a few years when it was absolutely bursting at the seams. It looks like they've got plans for an expansion with a
second terminal - up to 32 million.
Not been on the new airport monorail yet, but it comes straight into Luton Airport Parkway Station (you can see the monorail platform from the Thameslink one). I think it's about 5 minutes from the terminal to the Thameslink line, then about 15-20 mins from Luton Airport Parkway to proposed Wixams. You could probably land and get to the proposed park site in less than an hour if you clear passports quickly and have only hand luggage.
Getting to Stansted is a bit of a pain from Bedford though - not that far geographically, but takes LOADS longer than Luton and the public transport options are rubbish. It will be a bit better with EWR, but would still take probably over an hour on the train with changes. Luton Airport on the other hand has 6-8 trains an hour direct from Bedford and takes 25 minutes with no changes. I hate relying on train changes when going to the airport, so avoid like the plague. I always use Luton if possible, ditto for most in these parts.