I bought a Shark cordless vacuum in 2006. I loved it, because it had a hand vac that could easily be removed and replaced. Unfortunately, the battery exploded last year.
I replaced it with the Shark cordless vacuum (purple) that's on the market right now. I liked it at first, because it is pretty powerful. I wasn't crazy about the hand vac option though. You have to remove the brush and handle and add a nozzle attachment if you want to use it as a hand vac. After owning it for a couple weeks, the battery died out before I could finish my (very quick) vacuum jobs. I got the cheaper model that only came with one battery, so I didn't like the fact that I pretty much had to wait a whole day to recharge the one battery. You also have to remove the battery to charge it.
I contacted Shark to get a replacement battery. That was an exercise in frustration. I had to call them three times to get a commitment to send me a replacement battery. (Their call center is in India. The reps I spoke with had a difficult time with English, and were not very polite. And the calls had bad reception or a bad connection. My calls were disconnected many times.)
Finally, even after I got an e-mail confirmation that my battery was on its way, it never came. I called Shark AGAIN and was told that they did not know the reason why my battery wasn't shipped. But they gave me yet another 800 number to call. I got fed up and returned the vacuum to Target.
If you do end up getting the Shark, make sure you buy the one that comes with a spare battery. And keep the original packaging for at least a few weeks just in case you need to return or exchange it.
I ended up buying an Oreck cordless vacuum off of E-bay. I love it, however, it is an older model and it is hard to find these days. It is like my original Shark vacuum with the removable hand vac. So convenient! And the battery life is pretty good and it doesn't take long to recharge. It's great on hardwood, but not so good on carpet.
Good luck with your search! I was so sad when my old Shark vacuum broke, because it was one of the few appliances that made my life so much easier. I hate lugging out my giant vacuum cleaner and taking out the power outlet safety covers just to plug it in for a quick cleanup. I'm glad I found the Oreck :-)