Yup, totally wrong, sorry Pegglebot's DH!!
We've got three and they are fabulous dogs. Sweet, loving, quiet, incredibly cuddly, breathtaking to watch run and endlessly entertaining.
As bimandbam says, keeping them off the furniture isn't really an option and the food thievery (in fact thievery in general) is pretty normal behaviour as well. They've learned to be polite enough whilst people are eating but unattended food? Gone in seconds 
You soon learn not to leave food where they can pinch it, in our house that also means not leaving food + whippets unsupervised in the kitchen as one of them can and will jump up onto the worktops 
Mine all love playing with toys, both at home and out on walks, and it's absolutely amazing to watch them playing chase with each other. They've all got excellent recall and they go off lead on every walk but it is something that needs to be refreshed constantly, I'd never go out with them and not take some pretty tasty treats just so that coming back is always pretty awesome.
They're really chilled in the house, mine haven't been out yet today and they're currently all draped around the front room fast asleep. I always find there's something incredibly relaxing about being surrounded by snoozing whippets. They're really flexible as far as exercise goes, they'll go all day if you give them the opportunity but equally they're content with a 20 sprint around the field (or even a day off), especially if the weather is bad!!
Mine absolutely refuse to go out in the rain, a light drizzle they'll just about tolerate but if it's raining properly they hate it. They do need clothing for winter, mine have fleece jumpers for going out in winter and when it's really cold they get them layered up to keep them warm.
They're a lot more robust than they look and are very healthy as a breed. Some breeders are now screening for heart murmurs but it's currently a pre-emptive thing in case heart issues do show any signs of becoming a common issue in the future.
Some can be quite sensitive but not to the point of being neurotic. It's less about coping with normal, every day situations and more about how they cope with truly bad experiences. One of mine is what I would consider to be extremely sensitive for a whippet but he's still a great little dog and would have no issue being a pet in a busy family home. He's mostly a perfectly robust little thing just takes a little longer to get over a really horrible experience.
We've no children but they see my niece regularly and they're absolutely fabulous with her. So gentle and really happy to play with her. They also like saying hi to the kids who live on our street and they're always more than happy to get a bit of a fuss from strangers, adults or children, out on walks.
At homes they are so cuddly, it's almost impossible to sit down without a whippet ending up either on your lap or snuggled up against you. They make excellent hot water bottles in winter They're incredibly affectionate, always up for a cuddle, but they're also not necessarily going to trail after you all the time. Mine will if they think something interesting is going to happen but more often than not, especially if they're comfy, they'll stay put listening out for anything exciting. They know the sound of the dog biscuit box being opened or cheese being taken out of the fridge very well and all come running!!
They're bright little dogs and enjoy training if you make it fun for them but they don't need masses of mental stimulation to keep them happy. They are quite good at solving problems, one of mine is getting worrying close to working out how to open doors!! They're also endearingly mischievous and tend to be very silly when they're playing.
I could go on about them endlessly looks like I already have tbh but they are such amazing, funny, sweet and lovely little things.