Vacuum Cleaners Discussions

Everyone recommends a different vacuum--I thought I narrowed it down to a Miele canister (for my mix of hardwood and area rugs), but doing further research I found out about Simplicity and Sebo.  So what to buy?  The sales guy at my local shop suggested a Miele Polaris (S4 series).  I'm not thrilled about spending $400, but I want to get something that is effective (my husband and daughter have dust allergies), easy to use (I'm not a great housekeeper) and will last--my husband doesn't want to buy another vacuum cleaner (haha).  After reading their brochure, I called about the Miele Olympus (S2 series), which is $100 cheaper.  I'm not convinced the Polaris is worth the extra $100--any thoughts?  Can I add the carpet attachments to the Olympus if I need to down the road?  Is it worth looking into the Sebo or Simplicity?  I would have to drive an hour to a shop that sells either of those.  And then there's the Panasonic--cheaper, but worth it?  I appreciate any feedback I can get.