Got this phone around 7-8 months ago. As is comes out of the box it is not as a good NOKIA phone eg. 6100 which I had for a year. However, there are loads of free software and some useful software at a reasonable price and this is as useful as the best smartphone around. Some of the problems for those who want to buy this and which might be common with the TREO 650 are:
The case can get scratched easily. The phone has been known to be less resistant to shocks like falling down etc. I had mine falling down (reason later) twice and it still works without any problem.
The case supplied with the phone is not good. It does not have a lock or protector and the phone easily falls out. It is good for getting the phone out quickly but not if you want a reasonable lift. Case in leather is available from ebay. I bought one for Rs. 160 approx + shipment. Excellent made in China with belt clip etc.
The headset speaker and the main speaker at the back are quite good but liable to distort with high volume. There are programs available for increasing the volume but I would advise against this. Mine got a permanent distortion from the main speaker. Also, the headset speaker conked out. I got one for US $ 10 and changed it myself. Its ok now.
Phone with the right software (over and above Palm built in software) works well without any bugs or hanging.
MP3 works very well. However, the supplied headphone has only a mono playback. You need to buy a stereo headphone for really good sound. The supplied software Realplay allows you to sync with Media Player in MS WIndows.
Camera- not useful as supplied-very low resolution. There is a small program called Qset which allows jpeg compression to be adjusted. Once this is done the pictures are much better but nowhere good enough by todays standard.
Battery lasts about 2 days. Charging takes about 2.5 -3.0 hours. A charging/syn cable works well with USB port for charging. Not supplied with phone but on ebay costs Rs. 675/-.
Display is readable and quite bright in the shade. A bit low in bright direct sunlight. Resolution is just OK on the 600. The display needs a protector screen which are available for Rs. 200 or so and work well.
MS Office documents can be read and saved on both Treo and desktop/laptop. Sync is available for Outlook contacts, calendar, notes and tasks.
Sync is very fast.
As a phone, sound is very clear and no one has complained. Speaker phone gives a distorted sound if loud and is not the best. However, it works.
Bought it off ebay. Got it at Rs. 16900. Not available at less than Rs. 25-29k. Guess I was lucky.
Major gripe is that MMS does not work on Hutch. Dont know about other service providers.