John thanks for all the info, I will print it and study it in detail later. I am ruling out mail-order or refurbished equipment, because I personally don't have luck with that kind of deal, though I hear wonderful stories from others, I am always the one who gets "the one in a million" that is defective, or incomplete, etc. I found it is good to buy from a local store with a generous warranty/replacement policy. I know I am now limited to fewer units, but that should make it simpler for me to choose. Thanks again! Ken B