I would avoid writing good things about this phone here as they are already avaialble on HTC website. So let’s see what are the bads...
Minor Cons:
Below are the things which people can live without that’s why termed them "minor"
No "Gtalk" (it’s must when u hv gmail/facebook/twitter/weather)
No WiFi
No customizable skins/themes
Fixed focus camera
No "Task list" or "To Do" list in calendar
Now the major problem (really major!!!):
Phone has 256 MB ROM internal memory out of which only 87 MB is avaialble to the user at the time s/he buy it.
This ROM get’s consumed when you assign images to contacts, take photos, watch videos, set wallpaper (though image file stored in external microSD card), set lock screen background (though image file stored in external microSD card), set ringtone/sms tone/alarm tone (though sound file stored in external microSD card, install JAVA apps etc.
The above thing makes ROM to get full in 3-4 months of frequent use, or in some more time for occasional use (dangeroud if it happens after warranty period is over). and phone starts giving error when you launch any application it starts giving error (not enough memory to start the application).
Those who are already using it, just check you phone’s free ROM is it near to 256 MB? no way!!! It’s reducing and will reach zero soon.
This problem is not specific to handset, it’s a OS issue of not having proper memory management (to free up the space after file is no longer used in customization).
I have got my phone’s mother board replaced, several friends faced the same issue, even service centre person said he faced several complaints for the same handset with the same issue.
So better don’t go for it and if already have purchased, call HTC Customer Care (01202440055/1800113377) to register a complaint and ask for Refund/Replacement. (I’ve raised and got HTC Touch 2 in replacement as they don’t give refund).