My Sonicare Advance is probably the best investment on my mouth other than my dentist. The self-timer is one of the best features, especially early in the morning. I can't count how many times I left my mouth dirty because I didn't know how long I was brushing. With the easy beep every 30 seconds, I have gotten my quick oral care down to a science without even paying attention.
I was able to procure a brush head UV cleaner, and they advertised that brush heads are dirty. While the sonicare comes with a brush head protector, the UV cleaner was added protection from germs. However the only items needed are the Advance and a brush head. The heads don't exactly wear out in 6 months and you can stretch a bit, but they are expensive and will require replacement every year or so.