Which GPS should I buy? Can we compare features?

Is there a way to build an editable spreadsheet where we can list make/model number with a check list of features similar to Consumers Reports magazine.

Such a document would save a lot of unnecessary posts. OK, here’s what I want in my GPS.
= a must.
English interface

English Voice navigation Navigation
Search by Phone number *
pinyin input would be nice but I don’t think possible.

My friend has a pretty expensive mio that has most of these features. What is the difference between an expensive model or a cheap model from the same manufacturer. Is it just the extra features or does it affect the actually GPS engine.

The main differences of GPS models is some extra hardware features of the higher end models. Usually, bluetooth, which gives handsfree calling if you have a compatible bluetooth phone, and TMC (i.e. traffic messaging). There may also be some more accessories in the higher end models.