I bought the Crest spin brush because it was one of the cheapest - mistake number one I suppose - oh yeah- it was a mistake to buy it period.

This brush needs batteries - of coarse I didn't think to purchase these at the time of purchase so it was back to the store - my 2nd mistake.

The brush has two speeds - you never need the lower speed as the high speed doesn't have enough power to do the job.  I found it difficult to get into those hard to reach areas - behind and edges. 

I  complained but continued to use the brush thinking I would get used to it.  After about one week it just quit working. ...