M.B.
I know I'm a little late getting this to you, but I just bought a new vacuum and was overwhelmed with how many options there were. I really didn't think it could be that difficult. I ended up going to Fussnecker Sweeper repair and talking to a guy there. He told me that one of the most important things to look for is a metal beater brush. This will agitate the carpet the best.
I didn't want the mess of emptying a bagless, so that narrowed my options a lot. I got a Sanitaire upright and canister. It is technically a commercial line, but it is sold often to homes. I LOVE it - and who says that about a vacuum. My carpets actually look so much better. The upright doesn't have tools or any bells or whistles, but boy can it clean a carpet. The canister is great for all of the extras.
I looked on Consumer Reports for recommendations, but found that the top rated ones were rated poorly or average by people who had owned them for a while. Amazon was a good place for regular people reviews for this - and I never would have thought to look there for a vacuum cleaner.