Mio GPS comparison chart

Features	Mio C220	Mio C230	Mio C320	Mio C520	Mio C720t	Moov 200	Moov 310	Knight Rider
Maps	U.S.	U.S.	U.S.	U.S. Canada	U.S. Canada Mexico (ltd.)	U.S.	U.S.	U.S. Canada
Screen size	3.5″	3.5″	4.3″	4.3″	4.3″	3.5″	4.3″	4.3″
POIs	3.5 M	1.0 M	1.7 M	6.0 M	12.0 M	3.5 M	3.5 M	4.0 M
Speaks street names	No	Yes	No	Yes	Yes	Yes	Yes	Yes
TMC Traffic	No	No	No	No	Yes	No	Yes	No
Blue- tooth	No	No	No	Yes	Yes	No	No	No
MP3 player	No	No	Yes	Yes	Yes	No	No	No
Camera	No	No	No	No	Yes	No	No	No

POIs (Points of Interest) – I recommend getting a unit with at least 4.5 million. Here’s a post for further reading on points of interest (POIs).
Speaks street names – Formally known as text-to-speech, this function allows the device to
call out the name of the street for upcoming turns, so you’ll get “in
one-half mile, turn left on Oak Street,” rather than just “in one-half
mile, turn left.” A very helpful feature.
TMC traffic – A nice feature that isn’t quite ready for prime time. Expect lots of
inaccurate reports as well as incidents that aren’t reported. Delivered
via FM, this service is provided by the Traffic Message Channel, hence
you will sometimes see it referred to as FM-TMC. Here is a link to a coverage map.
Bluetooth for hands-free cell phone use – Another nice idea, with weak
implementation. In my experience, the sound quality
for the person hearing your voice is awful.