6610i the big brother of 6610, which for a long time ruled like a rajah in indian market, and helped NOKIA to build up volumes also.
Its software create problems when you start GPRS / EDGE. it will give an indication of connecting but, after 1.5 or more minutes, it shows a failure message. If by any chance a bit of water or drops enter inside, the key pad below the external key pad gets damaged & warranty is not effective if they detect water entry(service associates), especially nos 4, 6, 9 & 0 will give enough problems that you will go mad with the handset.
Also there is all probability that NOKIA would stop this model very shortly because they stopped 6610 a couple of months back. NOKIA never informs through media or through any other channel that their model is stopped.
I myself had the above problems after 7 months of 6610 usage, and now I am using 6020.