We replaced out DC14 with a DC24!
The DC14 is sturdy and has a good, long hose, but weighs a ton. Easy to shuffle backwards and forwards with, really difficult to carry up the stairs (I dropped mine, trying, and the bugger survived!)
The DC24 is very small and a lot lighter. it reaches further under smaller gaps, eg under furniture. I can carry it up and down the stairs. It needs emptying more frequently, though and the hose doesn't reach more than halfway up the stairs. Also, if pregnancy is giving you problems with loose ligaments, the ball design can make it a little hard on your wrists, as it's quite unstable.