I have used TomTom go 920 in the US, so my comparison of VX140 is against TomTom.
Maps: I used it to navigate inside Bangalore, from Bangalore to Chennai(door to door), Chennai to Tirupathi and Villuppuram to Bangalore. The maps were surprisingly accurate. There were 2 or 3 places on the highways where the roads were marked wrong(or the gps got confused) and I was shown as driving "off road". I have seen this in TomTom as well, so no surprises there. I was absolutely surprised to see the winding uphill road to upper Titupathi and the complete Upper Tirupathi map!
POI(Points of Interest): The POI data base is decent, it had the iskcon temple(s) in Bangalore but not the Gangamma Thimmaiah inn/community center near it. I haven’t explored POIs a lot.yet. POIs were an issue in TomTom too, so I was not surprised.
Routing: The routing and UI interface software is "mireo viagps"(see below for what’s in the device). There are 3 options: shortest, fastest and optimal. Ofcourse user never really knows what he/she wants and neither did I. Routing on the highways are good no matter what option you choose. Routing inside a city is sub optimial. It seems to be good in Bangalore but not in Chennai. May be the device does not know which is a good but busy road.
Misc Nice Features:
It has a light sensitive auto dimming brightness control+ optional auto switch to night colors. TomTom has the same feature.
Record route feature that remembers what route I took. Nice feature, TomTom does not have this.
Seems to be thin and well built(haven’t tried dropping it though!)
Cons
UI seemed to be slightly sluggish.
The music player is for all practical purposes useless. First it does not play high quality vbr mp3 files(plays normal 128kbps files fine). It cannot play music during navigation! TomTom can play mp3 during navigation and optionally pause while saying a navigation guidance.
Haven’t looked at the video player much. But it seems useless too.
The user interface for POI and address search are just OK. No easy way to browse streets or cities in the search screen.
No text to speech to tell street names. TomTom had this.
No customization to change map colors(other than ability to use day or night colors). TomTom had this.
Routing+UI software: Mireo ViaGps 3.0 black edition
MapMyIndia maps data with 600+ cities.
VX140 is a windows CE device with built-in GPS receiver. Mireo ViaGps and MapMyIndia data are just installed on this device.
The UI is not very user friendly and I know nobody reads the manual. UI still requires work.
I was apprehensive about how the one-way streets would be marked and used for routing in the VX140.
The maps were much better than what I expected.
Great start by MapMyIndia.
VX140 Recomended for tech savy people.
Not so tech savy people should try Garmin with the MapMyIndia Maps(garmin is known for its user friendly UI).